Show the home button immediately on startup to avoid flicker.

Longer term, I wonder if HomepageManager should provide the
ObservableSupplier itself and handle these updates internally without
ToolbarManager (or something else querying).

BUG=

Change-Id: I3ccedd220332fb2ea5bdca936c619934cbfe0420
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490491
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Patrick Noland <pnoland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820841}

chrome/android/java/src/org/chromium/chrome/browser/toolbar/HomeButton.java

@@ -56,8 +56,11 @@ public class HomeButton extends ChromeImageButton
      * @param isHomepageManagedByPolicy Supplier that tells if homepage is managed by policy.
      */
     public void init(ObservableSupplier<Boolean> homepageVisibility,
-            Callback<Context> onMenuClickCallback, Supplier<Boolean> isHomepageManagedByPolicy) {
-        homepageVisibility.addObserver((visible) -> updateContextMenuListener());
+            Callback<Context> onMenuClickCallback,
+            ObservableSupplier<Boolean> isHomepageManagedByPolicy) {
+        Callback<Boolean> contextUpdateCallback = (visible) -> updateContextMenuListener();
+        homepageVisibility.addObserver(contextUpdateCallback);
+        isHomepageManagedByPolicy.addObserver(contextUpdateCallback);
         mOnMenuClickCallback = onMenuClickCallback;
         mIsManagedByPolicySupplier = isHomepageManagedByPolicy;
         updateContextMenuListener();

chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java

@@ -56,8 +56,8 @@ import org.chromium.chrome.browser.ntp.FakeboxDelegate;
 import org.chromium.chrome.browser.ntp.IncognitoNewTabPage;
 import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.omnibox.LocationBar;
-import org.chromium.chrome.browser.omnibox.OmniboxFocusReason;
 import org.chromium.chrome.browser.omnibox.LocationBarCoordinator;
+import org.chromium.chrome.browser.omnibox.OmniboxFocusReason;
 import org.chromium.chrome.browser.omnibox.UrlFocusChangeListener;
 import org.chromium.chrome.browser.previews.Previews;
 import org.chromium.chrome.browser.previews.PreviewsAndroidBridge;
@@ -132,6 +132,8 @@ public class ToolbarManager implements UrlFocusChangeListener, ThemeColorObserve
     private final FullscreenManager.Observer mFullscreenObserver;
     private final ObservableSupplierImpl<Boolean> mHomeButtonVisibilitySupplier =
             new ObservableSupplierImpl<>();
+    private final ObservableSupplierImpl<Boolean> mHomepageManagedByPolicySupplier =
+            new ObservableSupplierImpl<>();
     private final ObservableSupplierImpl<Boolean> mIdentityDiscStateSupplier =
             new ObservableSupplierImpl<>();
     private final ObservableSupplier<Boolean> mOmniboxFocusStateSupplier;
@@ -675,9 +677,13 @@ public class ToolbarManager implements UrlFocusChangeListener, ThemeColorObserve
                 ()
                         -> identityDiscController.getForStartSurface(mStartSurfaceState),
                 startSurfaceSupplier);
-        mHomepageStateListener =
-                () -> mHomeButtonVisibilitySupplier.set(HomepageManager.isHomepageEnabled());
+        mHomepageStateListener = () -> {
+            mHomeButtonVisibilitySupplier.set(HomepageManager.isHomepageEnabled());
+            mHomepageManagedByPolicySupplier.set(HomepagePolicyManager.isHomepageManagedByPolicy());
+        };
         HomepageManager.getInstance().addListener(mHomepageStateListener);
+        mHomepageStateListener.onHomepageStateUpdated();
+
         if (toolbarLayout instanceof ToolbarPhone
                 && StartSurfaceConfiguration.isStartSurfaceEnabled()) {
             identityDiscController.addObserver(
@@ -686,8 +692,7 @@ public class ToolbarManager implements UrlFocusChangeListener, ThemeColorObserve
         HomeButton homeButton = mActivity.findViewById(R.id.home_button);
         if (homeButton != null) {
             homeButton.init(mHomeButtonVisibilitySupplier,
-                    HomepageManager.getInstance()::onMenuClick,
-                    HomepagePolicyManager::isHomepageManagedByPolicy);
+                    HomepageManager.getInstance()::onMenuClick, mHomepageManagedByPolicySupplier);
         }
         return toolbar;
     }

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/ToolbarPhone.java

@@ -51,7 +51,6 @@ import org.chromium.chrome.R;
 import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior;
 import org.chromium.chrome.browser.device.DeviceClassManager;
 import org.chromium.chrome.browser.feature_engagement.TrackerFactory;
-import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.omnibox.LocationBar;
 import org.chromium.chrome.browser.omnibox.LocationBarCoordinator;
@@ -477,8 +476,6 @@ public class ToolbarPhone extends ToolbarLayout
             }
         });
 
-        onHomeButtonUpdate(HomepageManager.isHomepageEnabled());
-
         updateVisualsForLocationBarState();
     }
 

chrome/android/java/src/org/chromium/chrome/browser/toolbar/top/ToolbarTablet.java

@@ -29,7 +29,6 @@ import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.NavigationPopup;
 import org.chromium.chrome.browser.download.DownloadUtils;
-import org.chromium.chrome.browser.homepage.HomepageManager;
 import org.chromium.chrome.browser.ntp.NewTabPage;
 import org.chromium.chrome.browser.omnibox.LocationBar;
 import org.chromium.chrome.browser.omnibox.LocationBarCoordinator;
@@ -270,9 +269,6 @@ public class ToolbarTablet extends ToolbarLayout
                 return getMenuButtonCoordinator().onEnterKeyPress();
             }
         });
-        if (HomepageManager.isHomepageEnabled()) {
-            mHomeButton.setVisibility(VISIBLE);
-        }
 
         mSaveOfflineButton.setOnClickListener(this);
         mSaveOfflineButton.setOnLongClickListener(this);

chrome/android/javatests/src/org/chromium/chrome/browser/homepage/HomepagePolicyIntegrationTest.java

@@ -92,7 +92,7 @@ public class HomepagePolicyIntegrationTest {
 
     @After
     public void tearDown() {
-        mTestServer.stopAndDestroyServer();
+        if (mTestServer != null) mTestServer.stopAndDestroyServer();
     }
 
     @Test
@@ -138,22 +138,24 @@ public class HomepagePolicyIntegrationTest {
                 ChromeTabUtils.getUrlStringOnUiThread(
                         mActivityTestRule.getActivity().getActivityTab()));
 
+        CriteriaHelper.pollUiThread(() -> {
+            ToolbarManager toolbarManager = mActivityTestRule.getActivity().getToolbarManager();
+            Criteria.checkThat(toolbarManager, Matchers.notNullValue());
+
+            HomeButton homeButton = toolbarManager.getHomeButtonForTesting();
+            Criteria.checkThat(homeButton, Matchers.notNullValue());
+            Criteria.checkThat("Home Button should be visible", homeButton.getVisibility(),
+                    Matchers.is(View.VISIBLE));
+            Criteria.checkThat("Long press for home button should be disabled",
+                    homeButton.isLongClickable(), Matchers.is(false));
+        });
+
         ChromeTabUtils.waitForTabPageLoaded(
                 mActivityTestRule.getActivity().getActivityTab(), TEST_URL, () -> {
                     ToolbarManager toolbarManager =
                             mActivityTestRule.getActivity().getToolbarManager();
-                    if (toolbarManager != null) {
-                        HomeButton homeButton = toolbarManager.getHomeButtonForTesting();
-                        if (homeButton != null) {
-                            Assert.assertEquals("Home Button should be visible", View.VISIBLE,
-                                    homeButton.getVisibility());
-
-                            // Context menu is disabled by checking long clickable
-                            Assert.assertFalse("Long press for home button should be disabled",
-                                    homeButton.isLongClickable());
-                            TouchCommon.singleClickView(homeButton);
-                        }
-                    }
+                    HomeButton homeButton = toolbarManager.getHomeButtonForTesting();
+                    TouchCommon.singleClickView(homeButton);
                 });
 
         Assert.assertEquals("After clicking HomeButton, URL should be back to Homepage", TEST_URL,

chrome/android/javatests/src/org/chromium/chrome/browser/toolbar/HomeButtonTest.java

@@ -30,7 +30,6 @@ import org.chromium.base.supplier.ObservableSupplierImpl;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.browser.homepage.HomepageManager;
-import org.chromium.chrome.browser.homepage.HomepagePolicyManager;
 import org.chromium.chrome.browser.homepage.HomepageTestRule;
 import org.chromium.chrome.browser.homepage.settings.HomepageSettings;
 import org.chromium.chrome.browser.settings.SettingsLauncher;
@@ -85,9 +84,10 @@ public class HomeButtonTest extends DummyUiActivityTestCase {
 
             mIdHomeButton = View.generateViewId();
             mHomeButton = new HomeButton(getActivity(), null);
+            ObservableSupplierImpl<Boolean> homepagePolicySupplier = new ObservableSupplierImpl<>();
+            homepagePolicySupplier.set(false);
             mHomeButton.init(new ObservableSupplierImpl<Boolean>(),
-                    HomepageManager.getInstance()::onMenuClick,
-                    HomepagePolicyManager::isHomepageManagedByPolicy);
+                    HomepageManager.getInstance()::onMenuClick, homepagePolicySupplier);
             mHomeButton.setId(mIdHomeButton);
             HomepageManager.getInstance().setSettingsLauncherForTesting(mSettingsLauncher);
             HomeButton.setSaveContextMenuForTests(true);