Split tab browser controls offset and constraint handling.

BUG=966272

Change-Id: I627f2137adb00a7acd312012d53d57050861426f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935288Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719192}

chrome/android/BUILD.gn

@@ -2726,7 +2726,7 @@ generate_jni("chrome_jni_headers") {
     "java/src/org/chromium/chrome/browser/suggestions/mostvisited/MostVisitedSitesBridge.java",
     "java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java",
     "java/src/org/chromium/chrome/browser/tab/InterceptNavigationDelegateImpl.java",
-    "java/src/org/chromium/chrome/browser/tab/TabBrowserControlsState.java",
+    "java/src/org/chromium/chrome/browser/tab/TabBrowserControlsConstraintsHelper.java",
     "java/src/org/chromium/chrome/browser/tab/TabFavicon.java",
     "java/src/org/chromium/chrome/browser/tab/TabImpl.java",
     "java/src/org/chromium/chrome/browser/tab/TabState.java",

chrome/android/chrome_java_sources.gni

@@ -1562,7 +1562,8 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/tab/TabAssociatedApp.java",
   "java/src/org/chromium/chrome/browser/tab/TabAttributeKeys.java",
   "java/src/org/chromium/chrome/browser/tab/TabAttributes.java",
-  "java/src/org/chromium/chrome/browser/tab/TabBrowserControlsState.java",
+  "java/src/org/chromium/chrome/browser/tab/TabBrowserControlsConstraintsHelper.java",
+  "java/src/org/chromium/chrome/browser/tab/TabBrowserControlsOffsetHelper.java",
   "java/src/org/chromium/chrome/browser/tab/TabBuilder.java",
   "java/src/org/chromium/chrome/browser/tab/TabContextMenuItemDelegate.java",
   "java/src/org/chromium/chrome/browser/tab/TabContextMenuPopulator.java",

chrome/android/chrome_junit_test_java_sources.gni

@@ -12,9 +12,9 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/DelayedScreenLockIntentHandlerTest.java",
   "junit/src/org/chromium/chrome/browser/InsetObserverViewTest.java",
   "junit/src/org/chromium/chrome/browser/IntentHeadersRecorderTest.java",
+  "junit/src/org/chromium/chrome/browser/SSLClientCertificateRequestTest.java",
   "junit/src/org/chromium/chrome/browser/ShadowDeviceConditions.java",
   "junit/src/org/chromium/chrome/browser/ShortcutHelperTest.java",
-  "junit/src/org/chromium/chrome/browser/SSLClientCertificateRequestTest.java",
   "junit/src/org/chromium/chrome/browser/autofill/AutofillUiUtilsTest.java",
   "junit/src/org/chromium/chrome/browser/background_sync/BackgroundSyncBackgroundTaskSchedulerTest.java",
   "junit/src/org/chromium/chrome/browser/background_sync/BackgroundSyncBackgroundTaskTest.java",
@@ -30,11 +30,11 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/browserservices/permissiondelegation/NotificationChannelPreserverTest.java",
   "junit/src/org/chromium/chrome/browser/browserservices/permissiondelegation/NotificationPermissionUpdaterTest.java",
   "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/ClientAppDataRecorderTest.java",
+  "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/CurrentPageVerifierTest.java",
   "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/TestVerifier.java",
   "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/TrustedWebActivityDisclosureControllerTest.java",
   "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/TrustedWebActivityOpenTimeRecorderTest.java",
   "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/TwaVerifierTest.java",
-  "junit/src/org/chromium/chrome/browser/browserservices/trustedwebactivityui/controller/CurrentPageVerifierTest.java",
   "junit/src/org/chromium/chrome/browser/compositor/CompositorSurfaceManagerImplTest.java",
   "junit/src/org/chromium/chrome/browser/compositor/animation/CompositorAnimationHandlerTest.java",
   "junit/src/org/chromium/chrome/browser/compositor/animation/CompositorAnimatorTest.java",
@@ -197,6 +197,7 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/suggestions/tile/TileGroupUnitTest.java",
   "junit/src/org/chromium/chrome/browser/survey/ChromeSurveyControllerTest.java",
   "junit/src/org/chromium/chrome/browser/tab/TabAttributesTest.java",
+  "junit/src/org/chromium/chrome/browser/tab/TabBrowserControlsOffsetHelperTest.java",
   "junit/src/org/chromium/chrome/browser/tab/TabUnitTest.java",
   "junit/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreUnitTest.java",
   "junit/src/org/chromium/chrome/browser/tabstate/TabStateUnitTest.java",
@@ -221,8 +222,8 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/webapps/addtohomescreen/AddToHomescreenDialogViewTest.java",
   "junit/src/org/chromium/chrome/browser/webapps/addtohomescreen/AddToHomescreenMediatorTest.java",
   "junit/src/org/chromium/chrome/browser/webapps/addtohomescreen/AddToHomescreenViewBinderTest.java",
-  "junit/src/org/chromium/chrome/browser/webshare/SharedFileCollatorTest.java",
   "junit/src/org/chromium/chrome/browser/webshare/ShareServiceImplTest.java",
+  "junit/src/org/chromium/chrome/browser/webshare/SharedFileCollatorTest.java",
   "junit/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheetSwipeDetectorTest.java",
   "junit/src/org/chromium/chrome/browser/widget/selection/SelectionDelegateTest.java",
 ]

chrome/android/features/vr/java/src/org/chromium/chrome/browser/vr/VrShell.java

@@ -44,7 +44,7 @@ import org.chromium.chrome.browser.page_info.PageInfoController;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabAssociatedApp;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabObserver;
 import org.chromium.chrome.browser.tab.TabRedirectHandler;
 import org.chromium.chrome.browser.tabmodel.ChromeTabCreator;
@@ -477,7 +477,7 @@ public class VrShell extends GvrLayout
         if (mTab != null) {
             initializeTabForVR();
             mTab.addObserver(mTabObserver);
-            TabBrowserControlsState.update(mTab, BrowserControlsState.HIDDEN, false);
+            TabBrowserControlsConstraintsHelper.update(mTab, BrowserControlsState.HIDDEN, false);
         }
         mTabObserver.onContentChanged(mTab);
     }
@@ -798,7 +798,7 @@ public class VrShell extends GvrLayout
                 View parent = mTab.getContentView();
                 mTab.getWebContents().setSize(parent.getWidth(), parent.getHeight());
             }
-            TabBrowserControlsState.update(mTab, BrowserControlsState.SHOWN, false);
+            TabBrowserControlsConstraintsHelper.update(mTab, BrowserControlsState.SHOWN, false);
         }
 
         mContentVirtualDisplay.destroy();

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

@@ -134,7 +134,7 @@ import org.chromium.chrome.browser.snackbar.SnackbarManager.SnackbarManageable;
 import org.chromium.chrome.browser.sync.ProfileSyncService;
 import org.chromium.chrome.browser.sync.SyncController;
 import org.chromium.chrome.browser.tab.Tab;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabImpl;
 import org.chromium.chrome.browser.tab.TabState;
 import org.chromium.chrome.browser.tabmodel.AsyncTabParamsManager;
@@ -831,7 +831,7 @@ public abstract class ChromeActivity<C extends ChromeActivityComponent>
                 // When resuming the activity, force an update to the fullscreen state to ensure a
                 // subactivity did not change the fullscreen configuration of this ChromeTab's
                 // renderer in the case where it was shared.
-                TabBrowserControlsState.updateEnabledState(tab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(tab);
             }
             VrModuleProvider.getDelegate().onActivityShown(this);
         } else {

chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java

@@ -30,7 +30,7 @@ import org.chromium.chrome.browser.compositor.layouts.eventfilter.ScrollDirectio
 import org.chromium.chrome.browser.compositor.overlays.SceneOverlay;
 import org.chromium.chrome.browser.compositor.scene_layer.SceneOverlayLayer;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.content_public.browser.SelectionPopupController;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.common.BrowserControlsState;
@@ -513,7 +513,7 @@ public class OverlayPanel extends OverlayPanelAnimation implements ActivityState
      *                should jump immediately.
      */
     public void updateBrowserControlsState(int current, boolean animate) {
-        TabBrowserControlsState.update(mActivity.getActivityTab(), current, animate);
+        TabBrowserControlsConstraintsHelper.update(mActivity.getActivityTab(), current, animate);
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/LayoutManager.java

@@ -39,7 +39,7 @@ import org.chromium.chrome.browser.native_page.NativePageFactory;
 import org.chromium.chrome.browser.tab.SadTab;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.Tab.TabHidingType;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabImpl;
 import org.chromium.chrome.browser.tab.TabThemeColorHelper;
 import org.chromium.chrome.browser.tabmodel.EmptyTabModelObserver;
@@ -514,7 +514,8 @@ public class LayoutManager implements LayoutUpdateHost, LayoutProvider,
     @Override
     public void releaseOverlayPanelContent() {
         if (getTabModelSelector() == null) return;
-        TabBrowserControlsState.updateEnabledState(getTabModelSelector().getCurrentTab());
+        TabBrowserControlsConstraintsHelper.updateEnabledState(
+                getTabModelSelector().getCurrentTab());
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/customtabs/features/toolbar/CustomTabBrowserControlsVisibilityDelegate.java

@@ -9,7 +9,7 @@ import org.chromium.chrome.browser.dependency_injection.ActivityScope;
 import org.chromium.chrome.browser.fullscreen.BrowserStateBrowserControlsVisibilityDelegate;
 import org.chromium.chrome.browser.fullscreen.ChromeFullscreenManager;
 import org.chromium.chrome.browser.tab.BrowserControlsVisibilityDelegate;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.content_public.common.BrowserControlsState;
 
 import javax.inject.Inject;
@@ -60,6 +60,6 @@ public class CustomTabBrowserControlsVisibilityDelegate
     }
 
     private void updateActiveTabFullscreenEnabledState() {
-        TabBrowserControlsState.updateEnabledState(mTabProvider.get());
+        TabBrowserControlsConstraintsHelper.updateEnabledState(mTabProvider.get());
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/fullscreen/ChromeFullscreenManager.java

@@ -33,7 +33,8 @@ import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.Tab.TabHidingType;
 import org.chromium.chrome.browser.tab.TabAttributeKeys;
 import org.chromium.chrome.browser.tab.TabAttributes;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
+import org.chromium.chrome.browser.tab.TabBrowserControlsOffsetHelper;
 import org.chromium.chrome.browser.tab.TabImpl;
 import org.chromium.chrome.browser.tabmodel.TabModelImpl;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
@@ -208,7 +209,7 @@ public class ChromeFullscreenManager extends FullscreenManager
                     @Override
                     public void run() {
                         if (getTab() != null) {
-                            TabBrowserControlsState.updateEnabledState(getTab());
+                            TabBrowserControlsConstraintsHelper.updateEnabledState(getTab());
                         } else if (!mBrowserVisibilityDelegate.canAutoHideBrowserControls()) {
                             setPositionsForTabToNonFullscreen();
                         }
@@ -449,7 +450,7 @@ public class ChromeFullscreenManager extends FullscreenManager
                     // We should hide browser controls first.
                     mPendingFullscreenOptions = options;
                     mIsEnteringPersistentModeState = true;
-                    TabBrowserControlsState.updateEnabledState(tab);
+                    TabBrowserControlsConstraintsHelper.updateEnabledState(tab);
                 }
             }
 
@@ -465,7 +466,7 @@ public class ChromeFullscreenManager extends FullscreenManager
             public void onFullscreenExited(Tab tab) {
                 // At this point, browser controls are hidden. Show browser controls only if it's
                 // permitted.
-                TabBrowserControlsState.update(tab, BrowserControlsState.SHOWN, true);
+                TabBrowserControlsConstraintsHelper.update(tab, BrowserControlsState.SHOWN, true);
             }
 
             @Override
@@ -617,8 +618,8 @@ public class ChromeFullscreenManager extends FullscreenManager
         if (mInGesture || mContentViewScrolling) return;
 
         // Update content viewport size only when the browser controls are not animating.
-        int topContentOffset = (int) mRendererTopContentOffset;
-        int bottomControlOffset = (int) mRendererBottomControlOffset;
+        int topContentOffset = mRendererTopContentOffset;
+        int bottomControlOffset = mRendererBottomControlOffset;
         if ((topContentOffset != 0 && topContentOffset != getTopControlsHeight())
                 && bottomControlOffset != 0 && bottomControlOffset != getBottomControlsHeight()) {
             return;
@@ -811,7 +812,7 @@ public class ChromeFullscreenManager extends FullscreenManager
     @Override
     public void setPositionsForTabToNonFullscreen() {
         Tab tab = getTab();
-        if (tab == null || TabBrowserControlsState.get(tab).canShow()) {
+        if (tab == null || TabBrowserControlsConstraintsHelper.get(tab).canShow()) {
             setPositionsForTab(0, 0, getTopControlsHeight());
         } else {
             setPositionsForTab(-getTopControlsHeight(), getBottomControlsHeight(), 0);
@@ -910,14 +911,14 @@ public class ChromeFullscreenManager extends FullscreenManager
 
         // Make sure the dominant control offsets have been set.
         Tab tab = getTab();
-        TabBrowserControlsState controlState = TabBrowserControlsState.get(tab);
-        if (controlState.offsetInitialized()) {
-            updateFullscreenManagerOffsets(false, controlState.topControlsOffset(),
-                    controlState.bottomControlsOffset(), controlState.contentOffset());
+        TabBrowserControlsOffsetHelper offsetHelper = TabBrowserControlsOffsetHelper.get(tab);
+        if (offsetHelper.offsetInitialized()) {
+            updateFullscreenManagerOffsets(false, offsetHelper.topControlsOffset(),
+                    offsetHelper.bottomControlsOffset(), offsetHelper.contentOffset());
         } else {
             showAndroidControls(false);
         }
-        TabBrowserControlsState.updateEnabledState(tab);
+        TabBrowserControlsConstraintsHelper.updateEnabledState(tab);
     }
 
     /**
@@ -973,7 +974,8 @@ public class ChromeFullscreenManager extends FullscreenManager
     private void runBrowserDrivenShowAnimation() {
         if (mControlsAnimator != null) return;
 
-        TabBrowserControlsState controlState = TabBrowserControlsState.get(getTab());
+        TabBrowserControlsConstraintsHelper controlState =
+                TabBrowserControlsConstraintsHelper.get(getTab());
         setOffsetOverridden(true);
 
         final float hiddenRatio = getBrowserControlHiddenRatio();

chrome/android/java/src/org/chromium/chrome/browser/fullscreen/FullscreenManager.java

@@ -11,7 +11,7 @@ import androidx.annotation.Nullable;
 
 import org.chromium.chrome.browser.fullscreen.FullscreenHtmlApiHandler.FullscreenHtmlApiDelegate;
 import org.chromium.chrome.browser.tab.Tab;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabImpl;
 import org.chromium.content_public.browser.GestureListenerManager;
 import org.chromium.content_public.browser.WebContents;
@@ -138,7 +138,7 @@ public abstract class FullscreenManager {
      */
     protected void enterPersistentFullscreenMode(FullscreenOptions options) {
         mHtmlApiHandler.enterPersistentFullscreenMode(options);
-        TabBrowserControlsState.updateEnabledState(getTab());
+        TabBrowserControlsConstraintsHelper.updateEnabledState(getTab());
         updateMultiTouchZoomSupport(false);
     }
 
@@ -148,7 +148,7 @@ public abstract class FullscreenManager {
      */
     public void exitPersistentFullscreenMode() {
         mHtmlApiHandler.exitPersistentFullscreenMode();
-        TabBrowserControlsState.updateEnabledState(getTab());
+        TabBrowserControlsConstraintsHelper.updateEnabledState(getTab());
         updateMultiTouchZoomSupport(true);
     }
 

chrome/android/java/src/org/chromium/chrome/browser/modaldialog/TabModalPresenter.java

@@ -27,7 +27,7 @@ import org.chromium.chrome.browser.omnibox.LocationBar;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabAttributeKeys;
 import org.chromium.chrome.browser.tab.TabAttributes;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.content_public.browser.SelectionPopupController;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.common.BrowserControlsState;
@@ -358,7 +358,7 @@ public class TabModalPresenter
         if (isShowing && areRendererInputEventsIgnored()) {
             mChromeFullscreenManager.showAndroidControls(true);
         } else {
-            TabBrowserControlsState.update(mActiveTab, BrowserControlsState.SHOWN,
+            TabBrowserControlsConstraintsHelper.update(mActiveTab, BrowserControlsState.SHOWN,
                     !mChromeFullscreenManager.offsetOverridden());
         }
     }

chrome/android/java/src/org/chromium/chrome/browser/tab/TabBrowserControlsState.java → chrome/android/java/src/org/chromium/chrome/browser/tab/TabBrowserControlsConstraintsHelper.java

@@ -4,7 +4,6 @@
 
 package org.chromium.chrome.browser.tab;
 
-import org.chromium.base.ObserverList.RewindableIterator;
 import org.chromium.base.annotations.NativeMethods;
 import org.chromium.content_public.browser.ImeAdapter;
 import org.chromium.content_public.browser.ImeEventObserver;
@@ -14,26 +13,21 @@ import org.chromium.content_public.common.BrowserControlsState;
 /**
  * Manages the state of tab browser controls.
  */
-public class TabBrowserControlsState extends TabWebContentsUserData implements ImeEventObserver {
-    private static final Class<TabBrowserControlsState> USER_DATA_KEY =
-            TabBrowserControlsState.class;
+public class TabBrowserControlsConstraintsHelper
+        extends TabWebContentsUserData implements ImeEventObserver {
+    private static final Class<TabBrowserControlsConstraintsHelper> USER_DATA_KEY =
+            TabBrowserControlsConstraintsHelper.class;
 
     private final TabImpl mTab;
-    private long mNativeTabBrowserControlsState; // Lazily initialized in |update|
+    private long mNativeTabBrowserControlsConstraintsHelper; // Lazily initialized in |update|
     private BrowserControlsVisibilityDelegate mVisibilityDelegate;
 
-    private int mTopControlsOffset;
-    private int mBottomControlsOffset;
-    private int mContentOffset;
-
-    /** {@code true} if offset was changed by compositor. */
-    private boolean mOffsetInitialized;
-
     public static void createForTab(Tab tab) {
-        tab.getUserDataHost().setUserData(USER_DATA_KEY, new TabBrowserControlsState(tab));
+        tab.getUserDataHost().setUserData(
+                USER_DATA_KEY, new TabBrowserControlsConstraintsHelper(tab));
     }
 
-    public static TabBrowserControlsState get(Tab tab) {
+    public static TabBrowserControlsConstraintsHelper get(Tab tab) {
         return tab.getUserDataHost().getUserData(USER_DATA_KEY);
     }
 
@@ -75,7 +69,7 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
     }
 
     /** Constructor */
-    private TabBrowserControlsState(Tab tab) {
+    private TabBrowserControlsConstraintsHelper(Tab tab) {
         super(tab);
         mTab = (TabImpl) tab;
         mTab.addObserver(new EmptyTabObserver() {
@@ -113,14 +107,6 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
                 updateEnabledState();
             }
 
-            @Override
-            public void onCrash(Tab tab) {
-                mTopControlsOffset = 0;
-                mBottomControlsOffset = 0;
-                mContentOffset = 0;
-                mOffsetInitialized = false;
-            }
-
             @Override
             public void onDestroyed(Tab tab) {
                 tab.removeObserver(this);
@@ -128,40 +114,12 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
         });
     }
 
-    /**
-     * Sets new top control and content offset from renderer.
-     * @param topControlsOffset Top control offset.
-     * @param contentOffset Content offset.
-     */
-    void setTopOffset(int topControlsOffset, int contentOffset) {
-        mTopControlsOffset = topControlsOffset;
-        mContentOffset = contentOffset;
-        notifyControlsOffsetChanged();
-    }
-
-    /**
-     * Sets new bottom control offset from renderer.
-     * @param bottomControlsOffset Bottom control offset.
-     */
-    void setBottomOffset(int bottomControlsOffset) {
-        mBottomControlsOffset = bottomControlsOffset;
-        notifyControlsOffsetChanged();
-    }
-
-    private void notifyControlsOffsetChanged() {
-        mOffsetInitialized = true;
-        RewindableIterator<TabObserver> observers = mTab.getTabObservers();
-        while (observers.hasNext()) {
-            observers.next().onBrowserControlsOffsetChanged(
-                    mTab, mTopControlsOffset, mBottomControlsOffset, mContentOffset);
-        }
-    }
-
     @Override
     public void destroyInternal() {
-        if (mNativeTabBrowserControlsState != 0) {
-            TabBrowserControlsStateJni.get().onDestroyed(
-                    mNativeTabBrowserControlsState, TabBrowserControlsState.this);
+        if (mNativeTabBrowserControlsConstraintsHelper != 0) {
+            TabBrowserControlsConstraintsHelperJni.get().onDestroyed(
+                    mNativeTabBrowserControlsConstraintsHelper,
+                    TabBrowserControlsConstraintsHelper.this);
         }
     }
 
@@ -197,12 +155,15 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
                         && current == BrowserControlsState.HIDDEN)) {
             return;
         }
-        if (mNativeTabBrowserControlsState == 0) {
-            mNativeTabBrowserControlsState =
-                    TabBrowserControlsStateJni.get().init(TabBrowserControlsState.this);
+        if (mNativeTabBrowserControlsConstraintsHelper == 0) {
+            mNativeTabBrowserControlsConstraintsHelper =
+                    TabBrowserControlsConstraintsHelperJni.get().init(
+                            TabBrowserControlsConstraintsHelper.this);
         }
-        TabBrowserControlsStateJni.get().updateState(mNativeTabBrowserControlsState,
-                TabBrowserControlsState.this, mTab.getWebContents(), constraints, current, animate);
+        TabBrowserControlsConstraintsHelperJni.get().updateState(
+                mNativeTabBrowserControlsConstraintsHelper,
+                TabBrowserControlsConstraintsHelper.this, mTab.getWebContents(), constraints,
+                current, animate);
     }
 
     /**
@@ -231,26 +192,6 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
         return constraints;
     }
 
-    /** @return Top control offset */
-    public int topControlsOffset() {
-        return mTopControlsOffset;
-    }
-
-    /** @return Bottom control offset */
-    public int bottomControlsOffset() {
-        return mBottomControlsOffset;
-    }
-
-    /** @return content offset */
-    public int contentOffset() {
-        return mContentOffset;
-    }
-
-    /** @return Whether the control offset is initialized by compositor. */
-    public boolean offsetInitialized() {
-        return mOffsetInitialized;
-    }
-
     // ImeEventObserver
 
     @Override
@@ -261,9 +202,11 @@ public class TabBrowserControlsState extends TabWebContentsUserData implements I
 
     @NativeMethods
     interface Natives {
-        long init(TabBrowserControlsState caller);
-        void onDestroyed(long nativeTabBrowserControlsState, TabBrowserControlsState caller);
-        void updateState(long nativeTabBrowserControlsState, TabBrowserControlsState caller,
-                WebContents webContents, int contraints, int current, boolean animate);
+        long init(TabBrowserControlsConstraintsHelper caller);
+        void onDestroyed(long nativeTabBrowserControlsConstraintsHelper,
+                TabBrowserControlsConstraintsHelper caller);
+        void updateState(long nativeTabBrowserControlsConstraintsHelper,
+                TabBrowserControlsConstraintsHelper caller, WebContents webContents, int contraints,
+                int current, boolean animate);
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/tab/TabBrowserControlsOffsetHelper.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.tab;
+
+import androidx.annotation.NonNull;
+
+import org.chromium.base.ObserverList.RewindableIterator;
+import org.chromium.base.UserData;
+
+/**
+ * Helper that coordinates the browser controls offsets from the perspective of a particular Tab.
+ */
+public class TabBrowserControlsOffsetHelper extends EmptyTabObserver implements UserData {
+    private static final Class<TabBrowserControlsOffsetHelper> USER_DATA_KEY =
+            TabBrowserControlsOffsetHelper.class;
+
+    private final TabImpl mTab;
+
+    private int mTopControlsOffset;
+    private int mBottomControlsOffset;
+    private int mContentOffset;
+
+    /** {@code true} if offset was changed by compositor. */
+    private boolean mOffsetInitialized;
+
+    /**
+     * Get (or lazily create) the offset helper for a particular Tab.
+     * @param tab The tab whose helper is being retrieved.
+     * @return The offset helper for a given tab.
+     */
+    @NonNull
+    public static TabBrowserControlsOffsetHelper get(Tab tab) {
+        TabBrowserControlsOffsetHelper helper = tab.getUserDataHost().getUserData(USER_DATA_KEY);
+        if (helper == null) {
+            helper = new TabBrowserControlsOffsetHelper(tab);
+            tab.getUserDataHost().setUserData(USER_DATA_KEY, helper);
+        }
+        return helper;
+    }
+
+    private TabBrowserControlsOffsetHelper(Tab tab) {
+        mTab = (TabImpl) tab;
+        tab.addObserver(this);
+    }
+
+    /**
+     * Sets new top control and content offset from renderer.
+     * @param topControlsOffset Top control offset.
+     * @param contentOffset Content offset.
+     */
+    void setTopOffset(int topControlsOffset, int contentOffset) {
+        if (mOffsetInitialized && topControlsOffset == mTopControlsOffset
+                && mContentOffset == contentOffset) {
+            return;
+        }
+        mTopControlsOffset = topControlsOffset;
+        mContentOffset = contentOffset;
+        notifyControlsOffsetChanged();
+    }
+
+    /**
+     * Sets new bottom control offset from renderer.
+     * @param bottomControlsOffset Bottom control offset.
+     */
+    void setBottomOffset(int bottomControlsOffset) {
+        if (mOffsetInitialized && mBottomControlsOffset == bottomControlsOffset) return;
+        mBottomControlsOffset = bottomControlsOffset;
+        notifyControlsOffsetChanged();
+    }
+
+    private void notifyControlsOffsetChanged() {
+        mOffsetInitialized = true;
+        RewindableIterator<TabObserver> observers = mTab.getTabObservers();
+        while (observers.hasNext()) {
+            observers.next().onBrowserControlsOffsetChanged(
+                    mTab, mTopControlsOffset, mBottomControlsOffset, mContentOffset);
+        }
+    }
+
+    @Override
+    public void onCrash(Tab tab) {
+        super.onCrash(tab);
+        mTopControlsOffset = 0;
+        mBottomControlsOffset = 0;
+        mContentOffset = 0;
+        mOffsetInitialized = false;
+    }
+
+    /** @return Top control offset */
+    public int topControlsOffset() {
+        return mTopControlsOffset;
+    }
+
+    /** @return Bottom control offset */
+    public int bottomControlsOffset() {
+        return mBottomControlsOffset;
+    }
+
+    /** @return content offset */
+    public int contentOffset() {
+        return mContentOffset;
+    }
+
+    /** @return Whether the control offset is initialized by compositor. */
+    public boolean offsetInitialized() {
+        return mOffsetInitialized;
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/tab/TabHelpers.java

@@ -43,7 +43,7 @@ public final class TabHelpers {
         }
         MediaSessionTabHelper.createForTab(tab);
         TaskTabHelper.createForTab(tab, parentTab);
-        TabBrowserControlsState.createForTab(tab);
+        TabBrowserControlsConstraintsHelper.createForTab(tab);
 
         // TODO(jinsukkim): Do this by having something observe new tab creation.
         if (tab.isIncognito()) CipherFactory.getInstance().triggerKeyGeneration();

chrome/android/java/src/org/chromium/chrome/browser/tab/TabStateBrowserControlsVisibilityDelegate.java

@@ -63,7 +63,7 @@ public class TabStateBrowserControlsVisibilityDelegate
                 if (!mIsFullscreenWaitingForLoad) return;
 
                 mIsFullscreenWaitingForLoad = false;
-                TabBrowserControlsState.updateEnabledState(mTab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             }
 
             private void cancelEnableFullscreenLoadDelay() {
@@ -94,13 +94,13 @@ public class TabStateBrowserControlsVisibilityDelegate
                 mHandler.removeMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD);
                 mHandler.sendEmptyMessageDelayed(
                         MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD, getLoadDelayMs());
-                TabBrowserControlsState.updateEnabledState(mTab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             }
 
             @Override
             public void onPageLoadStarted(Tab tab, String url) {
                 mIsFullscreenWaitingForLoad = !DomDistillerUrlUtils.isDistilledPage(url);
-                TabBrowserControlsState.updateEnabledState(mTab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             }
 
             @Override
@@ -108,13 +108,13 @@ public class TabStateBrowserControlsVisibilityDelegate
                 // Handle the case where a commit or prerender swap notification failed to arrive
                 // and the enable fullscreen message was never enqueued.
                 scheduleEnableFullscreenLoadDelayIfNecessary();
-                TabBrowserControlsState.updateEnabledState(mTab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             }
 
             @Override
             public void onPageLoadFailed(Tab tab, int errorCode) {
                 cancelEnableFullscreenLoadDelay();
-                TabBrowserControlsState.updateEnabledState(mTab);
+                TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             }
 
             @Override

chrome/android/java/src/org/chromium/chrome/browser/tab/TabViewAndroidDelegate.java

@@ -33,12 +33,12 @@ public class TabViewAndroidDelegate extends ViewAndroidDelegate {
 
     @Override
     public void onTopControlsChanged(int topControlsOffsetY, int contentOffsetY) {
-        TabBrowserControlsState.get(mTab).setTopOffset(topControlsOffsetY, contentOffsetY);
+        TabBrowserControlsOffsetHelper.get(mTab).setTopOffset(topControlsOffsetY, contentOffsetY);
     }
 
     @Override
     public void onBottomControlsChanged(int bottomControlsOffsetY, int bottomContentOffsetY) {
-        TabBrowserControlsState.get(mTab).setBottomOffset(bottomControlsOffsetY);
+        TabBrowserControlsOffsetHelper.get(mTab).setBottomOffset(bottomControlsOffsetY);
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java

@@ -304,7 +304,7 @@ public class TabWebContentsObserver extends TabWebContentsUserData {
                 observers.next().onDidAttachInterstitialPage(mTab);
             }
             mTab.notifyLoadProgress(mTab.getProgress());
-            TabBrowserControlsState.updateEnabledState(mTab);
+            TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             PolicyAuditor auditor = AppHooks.get().getPolicyAuditor();
             auditor.notifyCertificateFailure(
                     PolicyAuditorJni.get().getCertificateFailure(mTab.getWebContents()),
@@ -320,7 +320,7 @@ public class TabWebContentsObserver extends TabWebContentsUserData {
                 observers.next().onDidDetachInterstitialPage(mTab);
             }
             mTab.notifyLoadProgress(mTab.getProgress());
-            TabBrowserControlsState.updateEnabledState(mTab);
+            TabBrowserControlsConstraintsHelper.updateEnabledState(mTab);
             if (!mTab.maybeShowNativePage(mTab.getUrl(), false)) {
                 mTab.showRenderedPage();
             }

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java

@@ -46,7 +46,7 @@ import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.metrics.WebApkUma;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabBuilder;
 import org.chromium.chrome.browser.tab.TabDelegateFactory;
 import org.chromium.chrome.browser.tab.TabImpl;
@@ -567,8 +567,8 @@ public class WebappActivity extends BaseCustomTabActivity<WebappActivityComponen
                 if (navigation.hasCommitted() && navigation.isInMainFrame()) {
                     // Notify the renderer to permanently hide the top controls since they do
                     // not apply to fullscreen content views.
-                    TabBrowserControlsState.update(
-                            tab, TabBrowserControlsState.getConstraints(tab), true);
+                    TabBrowserControlsConstraintsHelper.update(
+                            tab, TabBrowserControlsConstraintsHelper.getConstraints(tab), true);
 
                     RecordHistogram.recordBooleanHistogram(
                             HISTOGRAM_NAVIGATION_STATUS, !navigation.isErrorPage());

chrome/android/javatests/src/org/chromium/chrome/browser/browserservices/TrustedWebActivityTest.java

@@ -39,7 +39,7 @@ import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.customtabs.CustomTabActivity;
 import org.chromium.chrome.browser.customtabs.CustomTabActivityTestRule;
 import org.chromium.chrome.browser.tab.Tab;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.browser.tab.TabThemeColorHelper;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.util.ChromeTabUtils;
@@ -254,6 +254,6 @@ public class TrustedWebActivityTest {
 
     public boolean getCanShowToolbarState(Tab tab) {
         return TestThreadUtils.runOnUiThreadBlockingNoException(
-                () -> TabBrowserControlsState.get(tab).canShow());
+                () -> TabBrowserControlsConstraintsHelper.get(tab).canShow());
     }
 }

chrome/android/javatests/src/org/chromium/chrome/browser/browserservices/TrustedWebActivityTestUtil.java

@@ -7,18 +7,18 @@ package org.chromium.chrome.browser.browserservices;
 import android.content.Intent;
 import android.support.test.InstrumentationRegistry;
 
+import androidx.browser.customtabs.CustomTabsService;
+import androidx.browser.customtabs.CustomTabsSessionToken;
+import androidx.browser.customtabs.TrustedWebUtils;
+
 import org.chromium.chrome.browser.customtabs.CustomTabActivity;
 import org.chromium.chrome.browser.customtabs.CustomTabsConnection;
 import org.chromium.chrome.browser.customtabs.CustomTabsTestUtils;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
 
 import java.util.concurrent.TimeoutException;
 
-import androidx.browser.customtabs.CustomTabsService;
-import androidx.browser.customtabs.CustomTabsSessionToken;
-import androidx.browser.customtabs.TrustedWebUtils;
-
 /**
  * Common utilities for Trusted Web Activity tests.
  */
@@ -50,8 +50,6 @@ public class TrustedWebActivityTestUtil {
     public static boolean isTrustedWebActivity(CustomTabActivity activity) {
         // A key part of the Trusted Web Activity UI is the lack of browser controls.
         return !TestThreadUtils.runOnUiThreadBlockingNoException(
-                () -> TabBrowserControlsState
-                        .get(activity.getActivityTab())
-                        .canShow());
+                () -> TabBrowserControlsConstraintsHelper.get(activity.getActivityTab()).canShow());
     }
 }

chrome/android/javatests/src/org/chromium/chrome/browser/webapps/WebappActivityTestRule.java

@@ -10,6 +10,8 @@ import android.support.test.InstrumentationRegistry;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.browser.customtabs.TrustedWebUtils;
+
 import org.junit.Assert;
 import org.junit.runner.Description;
 import org.junit.runners.model.Statement;
@@ -18,7 +20,7 @@ import org.chromium.base.test.util.UrlUtils;
 import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.ShortcutHelper;
 import org.chromium.chrome.browser.customtabs.CustomTabsTestUtils;
-import org.chromium.chrome.browser.tab.TabBrowserControlsState;
+import org.chromium.chrome.browser.tab.TabBrowserControlsConstraintsHelper;
 import org.chromium.chrome.test.ChromeActivityTestRule;
 import org.chromium.content_public.browser.test.util.Criteria;
 import org.chromium.content_public.browser.test.util.CriteriaHelper;
@@ -26,8 +28,6 @@ import org.chromium.content_public.browser.test.util.DOMUtils;
 import org.chromium.content_public.browser.test.util.JavaScriptUtils;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
 
-import androidx.browser.customtabs.TrustedWebUtils;
-
 /**
  * Custom {@link ChromeActivityTestRule} for tests using {@link WebappActivity}.
  */
@@ -152,7 +152,10 @@ public class WebappActivityTestRule extends ChromeActivityTestRule<WebappActivit
     public static void assertToolbarShowState(ChromeActivity activity, boolean showState) {
         Assert.assertEquals(showState,
                 TestThreadUtils.runOnUiThreadBlockingNoException(
-                        () -> TabBrowserControlsState.get(activity.getActivityTab()).canShow()));
+                        ()
+                                -> TabBrowserControlsConstraintsHelper
+                                           .get(activity.getActivityTab())
+                                           .canShow()));
     }
 
     /**

chrome/android/junit/src/org/chromium/chrome/browser/tab/TabBrowserControlsOffsetHelperTest.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.tab;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.base.ObserverList;
+import org.chromium.base.UserDataHost;
+import org.chromium.base.test.BaseRobolectricTestRunner;
+
+/** Unit tests for {@link TabBrowserControlsOffsetHelper}. */
+@RunWith(BaseRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class TabBrowserControlsOffsetHelperTest {
+    private final UserDataHost mUserDataHost = new UserDataHost();
+
+    @Mock
+    public TabImpl mTab;
+    @Mock
+    public TabObserver mDispatchedTabObserver;
+
+    private TabBrowserControlsOffsetHelper mHelper;
+    private TabObserver mRegisteredTabObserver;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        Mockito.when(mTab.getUserDataHost()).thenReturn(mUserDataHost);
+
+        ObserverList<TabObserver> observers = new ObserverList<>();
+        observers.addObserver(mDispatchedTabObserver);
+        Mockito.when(mTab.getTabObservers())
+                .thenAnswer(invocation -> observers.rewindableIterator());
+
+        ArgumentCaptor<TabObserver> observerArg = ArgumentCaptor.forClass(TabObserver.class);
+        mHelper = TabBrowserControlsOffsetHelper.get(mTab);
+        Mockito.verify(mTab).addObserver(observerArg.capture());
+        mRegisteredTabObserver = observerArg.getValue();
+
+        Assert.assertFalse(mHelper.offsetInitialized());
+    }
+
+    @Test
+    public void testSetTopOffset() {
+        int bottomValue = mHelper.bottomControlsOffset();
+
+        mHelper.setTopOffset(20, 50);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, 20, bottomValue, 50);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(20, mHelper.topControlsOffset());
+        Assert.assertEquals(50, mHelper.contentOffset());
+        Assert.assertEquals(bottomValue, mHelper.bottomControlsOffset());
+
+        // Different top offset, different content offset.
+        mHelper.setTopOffset(25, 55);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, 25, bottomValue, 55);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(25, mHelper.topControlsOffset());
+        Assert.assertEquals(55, mHelper.contentOffset());
+        Assert.assertEquals(bottomValue, mHelper.bottomControlsOffset());
+
+        // Different top offset, same content offset.
+        mHelper.setTopOffset(40, 55);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, 40, bottomValue, 55);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(40, mHelper.topControlsOffset());
+        Assert.assertEquals(55, mHelper.contentOffset());
+        Assert.assertEquals(bottomValue, mHelper.bottomControlsOffset());
+
+        // Same top offset, different content offset.
+        mHelper.setTopOffset(40, 60);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, 40, bottomValue, 60);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(40, mHelper.topControlsOffset());
+        Assert.assertEquals(60, mHelper.contentOffset());
+        Assert.assertEquals(bottomValue, mHelper.bottomControlsOffset());
+
+        // Same top offset, same content offset.  Duplicate values should not dispatch additional
+        // change notifications.
+        mHelper.setTopOffset(40, 60);
+        Mockito.verifyNoMoreInteractions(mDispatchedTabObserver);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(40, mHelper.topControlsOffset());
+        Assert.assertEquals(60, mHelper.contentOffset());
+        Assert.assertEquals(bottomValue, mHelper.bottomControlsOffset());
+    }
+
+    @Test
+    public void testSetBottomOffset() {
+        int topValue = mHelper.topControlsOffset();
+        int contentValue = mHelper.contentOffset();
+
+        mHelper.setBottomOffset(37);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, topValue, 37, contentValue);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(topValue, mHelper.topControlsOffset());
+        Assert.assertEquals(contentValue, mHelper.contentOffset());
+        Assert.assertEquals(37, mHelper.bottomControlsOffset());
+
+        // Different bottom offset.
+        mHelper.setBottomOffset(42);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, topValue, 42, contentValue);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(topValue, mHelper.topControlsOffset());
+        Assert.assertEquals(contentValue, mHelper.contentOffset());
+        Assert.assertEquals(42, mHelper.bottomControlsOffset());
+
+        // Same bottom offset.  Duplicate values should not dispatch additional change
+        // notifications.
+        mHelper.setBottomOffset(42);
+        Mockito.verifyNoMoreInteractions(mDispatchedTabObserver);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(topValue, mHelper.topControlsOffset());
+        Assert.assertEquals(contentValue, mHelper.contentOffset());
+        Assert.assertEquals(42, mHelper.bottomControlsOffset());
+    }
+
+    @Test
+    public void testTabCrashed() {
+        int initialBottomValue = mHelper.bottomControlsOffset();
+        mHelper.setTopOffset(11, 12);
+        Mockito.verify(mDispatchedTabObserver)
+                .onBrowserControlsOffsetChanged(mTab, 11, initialBottomValue, 12);
+        mHelper.setBottomOffset(13);
+        Mockito.verify(mDispatchedTabObserver).onBrowserControlsOffsetChanged(mTab, 11, 13, 12);
+        Assert.assertTrue(mHelper.offsetInitialized());
+        Assert.assertEquals(11, mHelper.topControlsOffset());
+        Assert.assertEquals(12, mHelper.contentOffset());
+        Assert.assertEquals(13, mHelper.bottomControlsOffset());
+
+        mRegisteredTabObserver.onCrash(mTab);
+        Assert.assertFalse(mHelper.offsetInitialized());
+        Assert.assertEquals(0, mHelper.topControlsOffset());
+        Assert.assertEquals(0, mHelper.contentOffset());
+        Assert.assertEquals(0, mHelper.bottomControlsOffset());
+    }
+}

chrome/browser/BUILD.gn

@@ -2638,8 +2638,8 @@ jumbo_static_library("browser") {
       "android/startup_bridge.h",
       "android/tab_android.cc",
       "android/tab_android.h",
-      "android/tab_browser_controls_state.cc",
-      "android/tab_browser_controls_state.h",
+      "android/tab_browser_controls_constraints_helper.cc",
+      "android/tab_browser_controls_constraints_helper.h",
       "android/tab_favicon.cc",
       "android/tab_favicon.h",
       "android/tab_printer.cc",

chrome/browser/android/tab_browser_controls_state.cc → chrome/browser/android/tab_browser_controls_constraints_helper.cc

@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/android/tab_browser_controls_state.h"
+#include "chrome/browser/android/tab_browser_controls_constraints_helper.h"
 
-#include "chrome/android/chrome_jni_headers/TabBrowserControlsState_jni.h"
+#include "chrome/android/chrome_jni_headers/TabBrowserControlsConstraintsHelper_jni.h"
 #include "chrome/common/chrome_render_frame.mojom.h"
 #include "content/public/browser/interstitial_page.h"
 #include "content/public/browser/render_frame_host.h"
@@ -15,19 +15,21 @@ using base::android::AttachCurrentThread;
 using base::android::JavaParamRef;
 using base::android::JavaRef;
 
-TabBrowserControlsState::TabBrowserControlsState(
+TabBrowserControlsConstraintsHelper::TabBrowserControlsConstraintsHelper(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj)
     : jobj_(env, obj) {}
 
-TabBrowserControlsState::~TabBrowserControlsState() = default;
+TabBrowserControlsConstraintsHelper::~TabBrowserControlsConstraintsHelper() =
+    default;
 
-void TabBrowserControlsState::OnDestroyed(JNIEnv* env,
-                                          const JavaParamRef<jobject>& obj) {
+void TabBrowserControlsConstraintsHelper::OnDestroyed(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
   delete this;
 }
 
-void TabBrowserControlsState::UpdateState(
+void TabBrowserControlsConstraintsHelper::UpdateState(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj,
     const JavaParamRef<jobject>& jweb_contents,
@@ -51,8 +53,9 @@ void TabBrowserControlsState::UpdateState(
   }
 }
 
-static jlong JNI_TabBrowserControlsState_Init(
+static jlong JNI_TabBrowserControlsConstraintsHelper_Init(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj) {
-  return reinterpret_cast<intptr_t>(new TabBrowserControlsState(env, obj));
+  return reinterpret_cast<intptr_t>(
+      new TabBrowserControlsConstraintsHelper(env, obj));
 }

chrome/browser/android/tab_browser_controls_state.h → chrome/browser/android/tab_browser_controls_constraints_helper.h

@@ -2,17 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_STATE_H_
-#define CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_STATE_H_
+#ifndef CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_CONSTRAINTS_HELPER_H_
+#define CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_CONSTRAINTS_HELPER_H_
 
 #include "base/android/scoped_java_ref.h"
 
-// Native TabBrowsreControlsState. Managed by Java class.
-class TabBrowserControlsState {
+// Dispatches changes to the browser controls constraints for a given tab.
+class TabBrowserControlsConstraintsHelper {
  public:
-  TabBrowserControlsState(JNIEnv* env,
-                          const base::android::JavaParamRef<jobject>& obj);
-  ~TabBrowserControlsState();
+  TabBrowserControlsConstraintsHelper(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj);
+  ~TabBrowserControlsConstraintsHelper();
 
   void UpdateState(JNIEnv* env,
                    const base::android::JavaParamRef<jobject>& obj,
@@ -27,4 +28,4 @@ class TabBrowserControlsState {
   base::android::ScopedJavaGlobalRef<jobject> jobj_;
 };
 
-#endif  // CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_STATE_H_
+#endif  // CHROME_BROWSER_ANDROID_TAB_BROWSER_CONTROLS_CONSTRAINTS_HELPER_H_