Revert "[Instant Start] Supports stack tab switcher."

This reverts commit 40a4a6b6.

Reason for revert: crbug.com/1132734

Original change's description:
> [Instant Start] Supports stack tab switcher.
>
> In this CL, we remove the check of stack tab switcher in
> TabUiFeatureUtilities#supportInstantStart(). Thus instant start can be
> enabled in MVP++. These changes can be verified by:
> - StartSurfaceTest#testShow_SingleAsHomepage_V2__Instant*.
>
> The following changes are made to support stack tab switcher in instant
> start:
> 1) Defer the creation of TabList in StackLayoutBase. It allows the
>    StackLayoutBase/StartSurfaceStackLayout to be created pre-native.
> 2) Add pending observer list in TabModelFilterProvider. Any observer
>    which is added before the TabModelFilterProvider is initialized, will
>    be cached and notified when the initialization is completed.
> 3) StartSurfaceLayout and StackLayoutBase will create its SceneLayer if
>    hasn't yet before calling updateSceneLayer().
>
> Bug: 1116449, 1076449
> Change-Id: I42a730045d4b9799d4bb08dc7d7dc947956f42ac
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2356167
> Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
> Reviewed-by: Theresa  <twellington@chromium.org>
> Reviewed-by: Matthew Jones <mdjones@chromium.org>
> Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
> Commit-Queue: Xi Han <hanxi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#810924}

TBR=hanxi@chromium.org,twellington@chromium.org,mdjones@chromium.org,wychen@chromium.org,hnakashima@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1116449
Bug: 1076449
Change-Id: Ib4ab05dfe04288d28bbfbd01ef2a0f01493795c1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437010Reviewed-by: Xi Han <hanxi@chromium.org>
Commit-Queue: Xi Han <hanxi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811468}

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceLayout.java

@@ -108,7 +108,7 @@ public class StartSurfaceLayout extends Layout implements StartSurface.OverviewM
 
         mIsInitialized = true;
         mStartSurface.initWithNative();
-        ensureSceneLayerCreated();
+        mSceneLayer = new TabListSceneLayer();
         mSceneLayer.setTabModelSelector(mTabModelSelector);
     }
 
@@ -214,7 +214,6 @@ public class StartSurfaceLayout extends Layout implements StartSurface.OverviewM
 
     @Override
     protected void updateLayout(long time, long dt) {
-        ensureSceneLayerCreated();
         super.updateLayout(time, dt);
         if (mLayoutTabs == null) return;
 
@@ -275,11 +274,6 @@ public class StartSurfaceLayout extends Layout implements StartSurface.OverviewM
         return mSceneLayer;
     }
 
-    private void ensureSceneLayerCreated() {
-        if (mSceneLayer != null) return;
-        mSceneLayer = new TabListSceneLayer();
-    }
-
     @Override
     public boolean handlesTabClosing() {
         return true;
@@ -484,7 +478,6 @@ public class StartSurfaceLayout extends Layout implements StartSurface.OverviewM
     protected void updateSceneLayer(RectF viewport, RectF contentViewport,
             LayerTitleCache layerTitleCache, TabContentManager tabContentManager,
             ResourceManager resourceManager, BrowserControlsStateProvider browserControls) {
-        ensureSceneLayerCreated();
         super.updateSceneLayer(viewport, contentViewport, layerTitleCache, tabContentManager,
                 resourceManager, browserControls);
         assert mSceneLayer != null;

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceStackLayout.java

@@ -35,7 +35,6 @@ public class StartSurfaceStackLayout extends StackLayout {
         mIsInitialized = true;
 
         super.onFinishNativeInitialization();
-        super.initWithNative();
         mCoordinator.initWithNative();
     }
 
@@ -45,9 +44,6 @@ public class StartSurfaceStackLayout extends StackLayout {
         mCoordinator.initialize();
 
         mController.showOverview(false);
-        if (!mIsInitialized) {
-            return;
-        }
         super.show(time, animate);
     }
 

chrome/android/features/start_surface/internal/javatests/src/org/chromium/chrome/features/start_surface/StartSurfaceTest.java

@@ -690,15 +690,7 @@ public class StartSurfaceTest {
                 instanceOf(StackLayout.class));
 
         pressBack();
-        onView(withId(R.id.primary_tasks_surface_view));
-
-        if (isInstantReturn()
-                && (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
-                        && Build.VERSION.SDK_INT < Build.VERSION_CODES.O)) {
-            // TODO(crbug.com/1092642): Fix androidx.test.espresso.PerformException issue when
-            // performing a single click on position: 0. See code below.
-            return;
-        }
+        onViewWaiting(withId(R.id.primary_tasks_surface_view));
 
         OverviewModeBehaviorWatcher hideWatcher =
                 TabUiTestHelper.createOverviewHideWatcher(mActivityTestRule.getActivity());

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabUiFeatureUtilities.java

@@ -175,8 +175,11 @@ public class TabUiFeatureUtilities {
      * @return Whether the instant start is supported.
      */
     public static boolean supportInstantStart(boolean isTablet) {
+        // TODO(crbug.com/1076449): Support instant start when the stack tab switcher is
+        // enabled.
         return !DeviceClassManager.enableAccessibilityLayout()
-                && CachedFeatureFlags.isEnabled(ChromeFeatureList.INSTANT_START) && !isTablet;
+                && CachedFeatureFlags.isEnabled(ChromeFeatureList.INSTANT_START) && !isTablet
+                && !StartSurfaceConfiguration.isStartSurfaceStackTabSwitcherEnabled();
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/app/flags/ChromeCachedFlags.java

@@ -56,7 +56,6 @@ public class ChromeCachedFlags {
                 ChromeFeatureList.CONDITIONAL_TAB_STRIP_ANDROID,
                 ChromeFeatureList.DOWNLOADS_AUTO_RESUMPTION_NATIVE,
                 ChromeFeatureList.HOMEPAGE_LOCATION_POLICY,
-                ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID,
                 ChromeFeatureList.IMMERSIVE_UI_MODE,
                 ChromeFeatureList.INSTANT_START,
                 ChromeFeatureList.INTEREST_FEED_CONTENT_SUGGESTIONS,

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

@@ -453,9 +453,6 @@ public class LayoutManager implements LayoutUpdateHost, LayoutProvider,
 
         // Initialize Layouts
         mStaticLayout.onFinishNativeInitialization();
-        if (mTabModelSelector == null) {
-            setTabModelSelector(selector);
-        }
 
         // Contextual Search scene overlay.
         mContextualSearchPanel = new ContextualSearchPanel(mContext, this, mOverlayPanelManager);
@@ -480,6 +477,10 @@ public class LayoutManager implements LayoutUpdateHost, LayoutProvider,
         // Set the dynamic resource loader for all overlay panels.
         mOverlayPanelManager.setDynamicResourceLoader(dynamicResourceLoader);
         mOverlayPanelManager.setContainerView(mContentContainer);
+
+        if (mTabModelSelector != selector) {
+            setTabModelSelector(selector);
+        }
     }
 
     // TODO(hanxi): Passes the TabModelSelectorSupplier in the constructor since the

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

@@ -198,8 +198,8 @@ public class LayoutManagerChrome
         mToolbarSwipeLayout.setTabModelSelector(selector, content);
         mOverviewListLayout.setTabModelSelector(selector, content);
         if (mOverviewLayout != null) {
-            mOverviewLayout.setTabModelSelector(selector, content);
             mOverviewLayout.onFinishNativeInitialization();
+            mOverviewLayout.setTabModelSelector(selector, content);
         }
     }
 

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/StackLayout.java

@@ -56,9 +56,6 @@ public class StackLayout extends StackLayoutBase {
     @Override
     public void setTabModelSelector(TabModelSelector modelSelector, TabContentManager manager) {
         super.setTabModelSelector(modelSelector, manager);
-        if (modelSelector.getTabModelFilterProvider().getCurrentTabModelFilter() == null) {
-            return;
-        }
         ArrayList<TabList> tabLists = new ArrayList<TabList>();
         tabLists.add(modelSelector.getTabModelFilterProvider().getTabModelFilter(false));
         tabLists.add(modelSelector.getTabModelFilterProvider().getTabModelFilter(true));

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/StackLayoutBase.java

@@ -43,7 +43,6 @@ import org.chromium.chrome.browser.compositor.layouts.phone.stack.Stack;
 import org.chromium.chrome.browser.compositor.layouts.phone.stack.StackTab;
 import org.chromium.chrome.browser.compositor.scene_layer.SceneLayer;
 import org.chromium.chrome.browser.compositor.scene_layer.TabListSceneLayer;
-import org.chromium.chrome.browser.flags.CachedFeatureFlags;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.tab.Tab;
@@ -227,6 +226,7 @@ public abstract class StackLayoutBase extends Layout {
     private final ViewGroup mViewContainer;
 
     private final GestureEventFilter mGestureEventFilter;
+    private final TabListSceneLayer mSceneLayer;
 
     private StackLayoutGestureHandler mGestureHandler;
 
@@ -236,8 +236,6 @@ public abstract class StackLayoutBase extends Layout {
     private final ObservableSupplier<BrowserControlsStateProvider> mBrowserControlsSupplier;
     private final BrowserControlsStateProvider.Observer mBrowserControlsObserver;
     private Callback<BrowserControlsStateProvider> mBrowserControlsSupplierObserver;
-    private TabListSceneLayer mSceneLayer;
-    private boolean mShowPending;
 
     private class StackLayoutGestureHandler implements GestureHandler {
         @Override
@@ -396,7 +394,7 @@ public abstract class StackLayoutBase extends Layout {
         mStacks = new ArrayList<Stack>();
         mStackRects = new ArrayList<RectF>();
         mViewContainer = new FrameLayout(getContext());
-
+        mSceneLayer = new TabListSceneLayer();
         mDpToPx = context.getResources().getDisplayMetrics().density;
         mBrowserControlsSupplier = browserControlsStateProviderSupplier;
         mBrowserControlsObserver = new BrowserControlsStateProvider.Observer() {
@@ -415,14 +413,6 @@ public abstract class StackLayoutBase extends Layout {
         mBrowserControlsSupplier.addObserver(mBrowserControlsSupplierObserver);
     }
 
-    public void initWithNative() {
-        ensureSceneLayerCreated();
-        if (mShowPending) {
-            mShowPending = false;
-            show(LayoutManager.time(), false);
-        }
-    }
-
     @Override
     public void destroy() {
         if (mBrowserControlsSupplier != null) {
@@ -451,7 +441,7 @@ public abstract class StackLayoutBase extends Layout {
      * switcher in both portrait and landscape mode) is enabled.
      */
     protected boolean isHorizontalTabSwitcherFlagEnabled() {
-        return CachedFeatureFlags.isEnabled(ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID);
+        return ChromeFeatureList.isEnabled(ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID);
     }
 
     /**
@@ -536,9 +526,7 @@ public abstract class StackLayoutBase extends Layout {
     @Override
     public void setTabModelSelector(TabModelSelector modelSelector, TabContentManager manager) {
         super.setTabModelSelector(modelSelector, manager);
-        if (mSceneLayer != null) {
         mSceneLayer.setTabModelSelector(modelSelector);
-        }
         resetScrollData();
 
         new TabModelSelectorTabModelObserver(mTabModelSelector) {
@@ -725,10 +713,6 @@ public abstract class StackLayoutBase extends Layout {
         super.onTabRestored(time, tabId);
         // Call show() so that new stack tabs and potentially new stacks get created.
         // TODO(twellington): add animation for showing the restored tab.
-        if (mSceneLayer == null) {
-            mShowPending = true;
-            return;
-        }
         show(time, false);
     }
 
@@ -1337,8 +1321,6 @@ public abstract class StackLayoutBase extends Layout {
 
     @Override
     protected void updateLayout(long time, long dt) {
-        if (mStacks.size() == 0) return;
-
         super.updateLayout(time, dt);
         boolean needUpdate = false;
 
@@ -1659,16 +1641,10 @@ public abstract class StackLayoutBase extends Layout {
         return mSceneLayer;
     }
 
-    private void ensureSceneLayerCreated() {
-        if (mSceneLayer != null) return;
-        mSceneLayer = new TabListSceneLayer();
-    }
-
     @Override
     protected void updateSceneLayer(RectF viewport, RectF contentViewport,
             LayerTitleCache layerTitleCache, TabContentManager tabContentManager,
             ResourceManager resourceManager, BrowserControlsStateProvider browserControls) {
-        ensureSceneLayerCreated();
         super.updateSceneLayer(viewport, contentViewport, layerTitleCache, tabContentManager,
                 resourceManager, browserControls);
         assert mSceneLayer != null;

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/Stack.java

@@ -24,7 +24,6 @@ import org.chromium.chrome.browser.compositor.layouts.components.LayoutTab;
 import org.chromium.chrome.browser.compositor.layouts.eventfilter.ScrollDirection;
 import org.chromium.chrome.browser.compositor.layouts.phone.StackLayoutBase;
 import org.chromium.chrome.browser.compositor.layouts.phone.stack.StackAnimation.OverviewAnimationType;
-import org.chromium.chrome.browser.flags.CachedFeatureFlags;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.TabList;
@@ -451,8 +450,6 @@ public abstract class Stack {
      * @return Whether or not the TabList represented by this TabStackState should be displayed.
      */
     public boolean isDisplayable() {
-        if (mTabList == null) return false;
-
         return !mTabList.isIncognito() || (!mIsDying && mTabList.getCount() > 0);
     }
 
@@ -1717,8 +1714,6 @@ public abstract class Stack {
      *                     restored if we're calling this while the switcher is already visible.
      */
     private void createStackTabs(boolean restoreState) {
-        if (mTabList == null) return;
-
         final int count = mTabList.getCount();
         if (count == 0) {
             cleanupTabs();
@@ -2032,7 +2027,7 @@ public abstract class Stack {
     }
 
     protected void updateCurrentMode(@Orientation int orientation) {
-        if (CachedFeatureFlags.isEnabled(ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID)) {
+        if (ChromeFeatureList.isEnabled(ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID)) {
             mCurrentMode = Orientation.LANDSCAPE;
         } else {
             mCurrentMode = orientation;

chrome/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorBase.java

@@ -58,7 +58,7 @@ public abstract class TabModelSelectorBase implements TabModelSelector, Incognit
         mIncognitoTabModel = incognitoModel;
         mActiveModelIndex = getModelIndex(mStartIncognito);
         assert mActiveModelIndex != MODEL_NOT_FOUND;
-        mTabModelFilterProvider.init(mTabModelFilterFactory, mTabModels);
+        mTabModelFilterProvider = new TabModelFilterProvider(mTabModelFilterFactory, mTabModels);
         addObserver(mTabModelFilterProvider);
 
         TabModelObserver tabModelObserver = new TabModelObserver() {

chrome/android/javatests/src/org/chromium/chrome/browser/compositor/layouts/LayoutManagerTest.java

@@ -156,9 +156,6 @@ public class LayoutManagerTest implements MockTabModelDelegate {
             TabModelUtils.setIndex(mTabModelSelector.getModel(true), incognitoIndexSelected);
         }
         mTabModelSelector.selectModel(incognitoSelected);
-        Assert.assertNotNull(
-                mTabModelSelector.getTabModelFilterProvider().getCurrentTabModelFilter());
-
         LayoutManagerHost layoutManagerHost = new MockLayoutHost(context);
         TabContentManager tabContentManager = new TabContentManager(context, null, false, null);
         tabContentManager.initWithNative();

chrome/browser/flags/android/java/src/org/chromium/chrome/browser/flags/CachedFeatureFlags.java

@@ -51,7 +51,6 @@ public class CachedFeatureFlags {
             put(ChromeFeatureList.ANDROID_PARTNER_CUSTOMIZATION_PHENOTYPE, true);
             put(ChromeFeatureList.CONDITIONAL_TAB_STRIP_ANDROID, false);
             put(ChromeFeatureList.HOMEPAGE_LOCATION_POLICY, false);
-            put(ChromeFeatureList.HORIZONTAL_TAB_SWITCHER_ANDROID, false);
             put(ChromeFeatureList.SERVICE_MANAGER_FOR_DOWNLOAD, false);
             put(ChromeFeatureList.SERVICE_MANAGER_FOR_BACKGROUND_PREFETCH, true);
             put(ChromeFeatureList.INTEREST_FEED_CONTENT_SUGGESTIONS, true);

chrome/browser/tabmodel/android/java/src/org/chromium/chrome/browser/tabmodel/TabModelFilterProvider.java

@@ -15,40 +15,23 @@ import java.util.List;
  */
 public class TabModelFilterProvider extends EmptyTabModelSelectorObserver {
     private List<TabModelFilter> mTabModelFilterList = Collections.emptyList();
-    private final List<TabModelObserver> mPendingTabModelObserver = new ArrayList<>();
 
     TabModelFilterProvider() {}
 
-    public void init(TabModelFilterFactory tabModelFilterFactory, List<TabModel> tabModels) {
-        assert mTabModelFilterList.isEmpty();
-        assert tabModels.size() > 0;
-
+    TabModelFilterProvider(TabModelFilterFactory tabModelFilterFactory, List<TabModel> tabModels) {
         List<TabModelFilter> filters = new ArrayList<>();
         for (int i = 0; i < tabModels.size(); i++) {
             filters.add(tabModelFilterFactory.createTabModelFilter(tabModels.get(i)));
         }
 
         mTabModelFilterList = Collections.unmodifiableList(filters);
-        // Registers the pending observers.
-        for (TabModelObserver observer : mPendingTabModelObserver) {
-            for (TabModelFilter tabModelFilter : mTabModelFilterList) {
-                tabModelFilter.addObserver(observer);
-            }
-        }
-        mPendingTabModelObserver.clear();
     }
 
     /**
-     * This method adds {@link TabModelObserver} to both {@link TabModelFilter}s. Caches the
-     * observer until {@link TabModelFilter}s are created.
+     * This method adds {@link TabModelObserver} to both {@link TabModelFilter}s.
      * @param observer {@link TabModelObserver} to add.
      */
     public void addTabModelFilterObserver(TabModelObserver observer) {
-        if (mTabModelFilterList.isEmpty()) {
-            mPendingTabModelObserver.add(observer);
-            return;
-        }
-
         for (int i = 0; i < mTabModelFilterList.size(); i++) {
             mTabModelFilterList.get(i).addObserver(observer);
         }
@@ -59,11 +42,6 @@ public class TabModelFilterProvider extends EmptyTabModelSelectorObserver {
      * @param observer {@link TabModelObserver} to remove.
      */
     public void removeTabModelFilterObserver(TabModelObserver observer) {
-        if (mTabModelFilterList.isEmpty() && !mPendingTabModelObserver.isEmpty()) {
-            mPendingTabModelObserver.remove(observer);
-            return;
-        }
-
         for (int i = 0; i < mTabModelFilterList.size(); i++) {
             mTabModelFilterList.get(i).removeObserver(observer);
         }
@@ -105,7 +83,6 @@ public class TabModelFilterProvider extends EmptyTabModelSelectorObserver {
         for (int i = 0; i < mTabModelFilterList.size(); i++) {
             mTabModelFilterList.get(i).destroy();
         }
-        mPendingTabModelObserver.clear();
     }
 
     private void markTabStateInitialized() {

chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/tabmodel/MockTabModel.java

@@ -42,7 +42,6 @@ public class MockTabModel extends EmptyTabModel implements IncognitoTabModel {
     private final ArrayList<Tab> mTabs = new ArrayList<Tab>();
     private final boolean mIncognito;
     private final MockTabModelDelegate mDelegate;
-    private boolean mIsCurrentModel;
 
     public MockTabModel(boolean incognito, MockTabModelDelegate delegate) {
         mIncognito = incognito;
@@ -123,13 +122,4 @@ public class MockTabModel extends EmptyTabModel implements IncognitoTabModel {
 
     @Override
     public void removeIncognitoObserver(IncognitoTabModelObserver observer) {}
-
-    @Override
-    public boolean isCurrentModel() {
-        return mIsCurrentModel;
-    }
-
-    public void setAsCurrentModelForTesting() {
-        mIsCurrentModel = true;
-    }
 }

chrome/test/android/javatests/src/org/chromium/chrome/test/util/browser/tabmodel/MockTabModelSelector.java

@@ -64,10 +64,4 @@ public class MockTabModelSelector extends TabModelSelectorBase {
     public int getTotalTabCount() {
         throw new UnsupportedOperationException();
     }
-
-    @Override
-    public void selectModel(boolean incognito) {
-        super.selectModel(incognito);
-        ((MockTabModel) getModel(incognito)).setAsCurrentModelForTesting();
-    }
 }