Records handlers which failed to consume back press.

Refactor BackPressHandler so that it can return a value to indicate
whether back press is correctly consumed. If a handler fails,
the back press will pass to remaining handlers.
Introduce BackPressResult to represent the result of handling back
press. The reason why boolean is not used is because I want to
differentiate between handleBackPress and traditional onBackPressed,
and also to emphasize not handling back press is a failure which
may have already made chrome working inappropriately.

For some handlers it might be hard to verify, so we return UNKNOWN.

This CL also adds a new histogram to record them.

Bug: 1414606, 1414832
Change-Id: Ib841f9626fc30b73682f0f8d079a65288a894850
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4251777
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Donn Denman <donnd@chromium.org>
Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Reviewed-by: Sinan Sahin <sinansahin@google.com>
Commit-Queue: Lijin Shen <lazzzis@google.com>
Cr-Commit-Position: refs/heads/main@{#1108448}

chrome/android/features/keyboard_accessory/internal/java/src/org/chromium/chrome/browser/keyboard_accessory/ManualFillingCoordinator.java

@@ -77,8 +77,8 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        mMediator.handleBackPress();
+    public @BackPressResult int handleBackPress() {
+        return mMediator.handleBackPress();
     }
 
     @Override

chrome/android/features/keyboard_accessory/internal/java/src/org/chromium/chrome/browser/keyboard_accessory/ManualFillingMediator.java

@@ -298,9 +298,8 @@ boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        boolean ret = onBackPressed();
-        assert ret : "This should only be called when mBackPressChangedSupplier yields true";
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

chrome/android/features/start_surface/java/src/org/chromium/chrome/features/start_surface/StartSurfaceMediator.java

@@ -973,9 +973,10 @@ void onHide() {
     }
 
     @Override
-    public void handleBackPress() {
-        onBackPressedInternal();
+    public @BackPressResult int handleBackPress() {
+        boolean ret = onBackPressedInternal();
         notifyBackPressStateChanged();
+        return ret ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

chrome/android/features/start_surface/java/src/org/chromium/chrome/features/tasks/SingleTabSwitcherMediator.java

@@ -252,8 +252,8 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        selectTheCurrentTab();
+    public @BackPressResult int handleBackPress() {
+        return BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -221,9 +221,10 @@ public boolean handleBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         mMediator.hideDialog(true);
         RecordUserAction.record("TabGridDialog.Exit");
+        return isVisible() ? BackPressResult.FAILURE : BackPressResult.SUCCESS;
     }
 
     @Override

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

@@ -234,8 +234,8 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        mMediator.handleBackPress();
+    public @BackPressResult int handleBackPress() {
+        return mMediator.handleBackPress();
     }
 
     @Override

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

@@ -416,8 +416,9 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        if (mTabGridDialogController != null) mTabGridDialogController.handleBackPress();
+    public @BackPressResult int handleBackPress() {
+        if (mTabGridDialogController != null) return mTabGridDialogController.handleBackPress();
+        return BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -291,8 +291,10 @@ public boolean handleBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
+        int result = isEditorVisible() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
         mNavigationProvider.goBack();
+        return result;
     }
 
     @Override

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

@@ -882,9 +882,8 @@ private boolean onBackPressedInternal() {
     }
 
     @Override
-    public void handleBackPress() {
-        boolean ret = onBackPressedInternal();
-        assert ret;
+    public @BackPressResult int handleBackPress() {
+        return onBackPressedInternal() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -44,7 +44,9 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {}
+    public @BackPressResult int handleBackPress() {
+        return BackPressResult.FAILURE;
+    }
 
     @Override
     public ObservableSupplier<Boolean> getHandleBackPressChangedSupplier() {

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

@@ -34,8 +34,8 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        onBackPressed();
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -397,7 +397,7 @@ public abstract class ChromeActivity<C extends ChromeActivityComponent>
     // returned by {@link isInPictureInPictureMode}.
     private boolean mLastPictureInPictureModeForTesting;
 
-    protected BackPressManager mBackPressManager = new BackPressManager();
+    protected BackPressManager mBackPressManager = new BackPressManager(this::handleOnBackPressed);
     private TextBubbleBackPressHandler mTextBubbleBackPressHandler;
     private SelectionPopupBackPressHandler mSelectionPopupBackPressHandler;
     private Callback<TabModelSelector> mSelectionPopupBackPressInitCallback;
@@ -2193,8 +2193,6 @@ protected boolean isFirstActivity() {
 
     /** Handles back press events for Chrome in various states. */
     protected final boolean handleOnBackPressed() {
-        assert !BackPressManager.isEnabled()
-            : "Back press should be handled by implementors of BackPressHandler if enabled";
         RecordUserAction.record(
                 mNativeInitialized ? "SystemBack" : "SystemBackBeforeNativeInitialized");
         if (isActivityFinishingOrDestroyed()) {

chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkManager.java

@@ -375,9 +375,8 @@ private void onBackPressStateChanged() {
 
     // BackPressHandler Overrides
     @Override
-    public void handleBackPress() {
-        var ret = onBackPressed();
-        assert ret;
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -987,8 +987,7 @@ public ObservableSupplier<Boolean> getHandleBackPressChangedSupplier() {
     }
 
     @Override
-    public void handleBackPress() {
-        boolean ret = onBackPressed();
-        assert ret;
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 }

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

@@ -1155,14 +1155,14 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         for (SceneOverlay sceneOverlay : mSceneOverlays) {
             Boolean enabled = sceneOverlay.getHandleBackPressChangedSupplier().get();
             if (enabled != null && enabled) {
-                sceneOverlay.handleBackPress();
-                return;
+                return sceneOverlay.handleBackPress();
             }
         }
+        return BackPressResult.FAILURE;
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/findinpage/FindToolbar.java

@@ -379,8 +379,11 @@ public void onClick(View v) {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
+        int result =
+                shouldDeactivateByBackPress() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
         deactivate();
+        return result;
     }
 
     @Override
@@ -682,7 +685,7 @@ protected void handleDeactivation(boolean clearSelection) {
 
     private void setCurrentState(@FindLocationBarState int state) {
         mCurrentState = state;
-        mBackPressStateSupplier.set(mCurrentState == FindLocationBarState.SHOWN);
+        mBackPressStateSupplier.set(shouldDeactivateByBackPress());
 
         // Notify the observers if we hit the transition states.
         if (mObserver != null) {
@@ -706,6 +709,11 @@ private void setCurrentState(@FindLocationBarState int state) {
         }
     }
 
+    // Whether the find toolbar should be deactivated by back press.
+    private boolean shouldDeactivateByBackPress() {
+        return mCurrentState == FindLocationBarState.SHOWN;
+    }
+
     /**
      * Requests focus for the query input field and shows the keyboard.
      */

chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java

@@ -418,11 +418,11 @@ public void onStart() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         // Terminate if we are still waiting for the native or for Android EDU / GAIA Child checks.
         if (!mPostNativeAndPolicyPagesCreated) {
             abortFirstRunExperience();
-            return;
+            return BackPressResult.SUCCESS;
         }
 
         mFirstRunFlowSequencer.updateFirstRunProperties(mFreProperties);
@@ -437,6 +437,7 @@ public void handleBackPress() {
         } else {
             setCurrentItemForPager(position);
         }
+        return BackPressResult.SUCCESS;
     }
 
     // FirstRunPageDelegate:

chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivityBase.java

@@ -173,7 +173,7 @@ public ObservableSupplier<Boolean> getHandleBackPressChangedSupplier() {
      * Called when back press is intercepted.
      */
     @Override
-    public abstract void handleBackPress();
+    public abstract @BackPressResult int handleBackPress();
 
     protected void flushPersistentData() {
         if (mNativeInitialized) {

chrome/android/java/src/org/chromium/chrome/browser/firstrun/LightweightFirstRunActivity.java

@@ -215,8 +215,9 @@ public void onDestroy() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         abortFirstRunExperience();
+        return BackPressResult.SUCCESS;
     }
 
     private void abortFirstRunExperience() {

chrome/android/java/src/org/chromium/chrome/browser/history/HistoryManager.java

@@ -689,9 +689,8 @@ public boolean onBackPressed() {
 
     // BackPressHandler implementation.
     @Override
-    public void handleBackPress() {
-        var ret = onBackPressed();
-        assert ret;
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

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

@@ -152,9 +152,10 @@ public boolean onBackPressed() {
     }
 
     @Override
-    public void handleBackPress() {
-        assert shouldInterceptBackPress();
+    public @BackPressResult int handleBackPress() {
+        int result = shouldInterceptBackPress() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
         mPresenter.dismissCurrentDialog(DialogDismissalCause.NAVIGATE_BACK_OR_TOUCH_OUTSIDE);
+        return result;
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/read_later/ReadingListBackPressHandler.java

@@ -35,11 +35,13 @@ protected void onObservingDifferentTab(Tab tab, boolean hint) {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         Tab tab = mActivityTabProvider.get();
+        int result = shouldInterceptBackPress() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
         ReadingListUtils.showReadingList(tab.isIncognito());
         WebContents webContents = tab.getWebContents();
         if (webContents != null) webContents.dispatchBeforeUnload(false);
+        return result;
     }
 
     @Override
@@ -53,8 +55,11 @@ public void destroy() {
     }
 
     private void onBackPressStateChanged() {
+        mBackPressChangedSupplier.set(shouldInterceptBackPress());
+    }
+
+    private boolean shouldInterceptBackPress() {
         Tab tab = mActivityTabProvider.get();
-        mBackPressChangedSupplier.set(
-                tab != null && tab.getLaunchType() == TabLaunchType.FROM_READING_LIST);
+        return tab != null && tab.getLaunchType() == TabLaunchType.FROM_READING_LIST;
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/tasks/ReturnToChromeUtil.java

@@ -126,12 +126,13 @@ private void onBackPressStateChanged() {
         }
 
         @Override
-        public void handleBackPress() {
+        public @BackPressResult int handleBackPress() {
             Tab tab = mActivityTabProvider.get();
-            assert tab != null
-                    && !tab.canGoBack()
+            boolean res = tab != null && !tab.canGoBack() && isTabFromStartSurface(tab);
+            assert res
                 : String.format("tab %s; back press state %s", tab, tab != null && tab.canGoBack());
             mOnBackPressedCallback.run();
+            return res ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
         }
 
         @Override

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

@@ -2123,7 +2123,7 @@ private void onBackPressStateChanged() {
     }
 
     @Override
-    public void handleBackPress() {
+    public @BackPressResult int handleBackPress() {
         boolean ret = back();
         if (!ret) {
             var bc = mBottomControlsCoordinatorSupplier != null
@@ -2138,6 +2138,7 @@ public void handleBackPress() {
                     tab != null && tab.isDestroyed());
             assert false : msg;
         }
+        return ret ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/vr/ArDelegateImpl.java

@@ -29,8 +29,8 @@ public boolean hasActiveArSession() {
     }
 
     @Override
-    public void handleBackPress() {
-        onBackPressed();
+    public @BackPressResult int handleBackPress() {
+        return onBackPressed() ? BackPressResult.SUCCESS : BackPressResult.FAILURE;
     }
 
     @Override