Upstream oodles of Chrome for Android code into Chromium.

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

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeActivity.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeActivity.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeActivity.java
new file mode 100644
index 0000000000000000000000000000000000000000..1097a84f9360e45441cb7d36f898ef98dde989c6
--- /dev/null
+++ b/chrome/android/java_staging/src/org/chromium/chrome/browser/ChromeActivity.java
@@ -0,0 +1,798 @@
+// Copyright 2015 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;
+
+import android.annotation.SuppressLint;
+import android.app.Activity;
+import android.app.SearchManager;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.graphics.Bitmap;
+import android.graphics.Rect;
+import android.os.Build;
+import android.os.Looper;
+import android.os.MessageQueue;
+import android.os.SystemClock;
+import android.preference.PreferenceManager;
+import android.provider.Settings;
+import android.provider.Settings.SettingNotFoundException;
+import android.util.DisplayMetrics;
+import android.view.Display;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.Surface;
+import android.view.View;
+import android.view.Window;
+import android.view.WindowManager;
+import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityManager.AccessibilityStateChangeListener;
+import android.view.accessibility.AccessibilityManager.TouchExplorationStateChangeListener;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.base.BaseSwitches;
+import org.chromium.base.CommandLine;
+import org.chromium.base.metrics.RecordUserAction;
+import org.chromium.chrome.browser.IntentHandler.IntentHandlerDelegate;
+import org.chromium.chrome.browser.IntentHandler.TabOpenType;
+import org.chromium.chrome.browser.compositor.layouts.content.ContentOffsetProvider;
+import org.chromium.chrome.browser.compositor.layouts.content.TabContentManager;
+import org.chromium.chrome.browser.contextualsearch.ContextualSearchManager;
+import org.chromium.chrome.browser.device.DeviceClassManager;
+import org.chromium.chrome.browser.fullscreen.FullscreenManager;
+import org.chromium.chrome.browser.gsa.ContextReporter;
+import org.chromium.chrome.browser.gsa.GSAServiceClient;
+import org.chromium.chrome.browser.gsa.GSAState;
+import org.chromium.chrome.browser.infobar.InfoBarContainer;
+import org.chromium.chrome.browser.init.AsyncInitializationActivity;
+import org.chromium.chrome.browser.metrics.LaunchMetrics;
+import org.chromium.chrome.browser.metrics.UmaSessionStats;
+import org.chromium.chrome.browser.nfc.BeamController;
+import org.chromium.chrome.browser.nfc.BeamProvider;
+import org.chromium.chrome.browser.omaha.OmahaClient;
+import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomizations;
+import org.chromium.chrome.browser.policy.PolicyManager.PolicyChangeListener;
+import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
+import org.chromium.chrome.browser.share.ShareHelper;
+import org.chromium.chrome.browser.sync.ProfileSyncService;
+import org.chromium.chrome.browser.tabmodel.ChromeTabCreator;
+import org.chromium.chrome.browser.tabmodel.EmptyTabModel;
+import org.chromium.chrome.browser.tabmodel.TabCreatorManager;
+import org.chromium.chrome.browser.tabmodel.TabModel;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+import org.chromium.chrome.browser.tabmodel.TabModelSelectorTabObserver;
+import org.chromium.chrome.browser.tabmodel.TabModelUtils;
+import org.chromium.chrome.browser.tabmodel.TabWindowManager;
+import org.chromium.chrome.browser.util.FeatureUtilities;
+import org.chromium.content.browser.ContentReadbackHandler;
+import org.chromium.content.browser.ContentViewCore;
+import org.chromium.content.common.ContentSwitches;
+import org.chromium.content_public.browser.readback_types.ReadbackResponse;
+import org.chromium.ui.base.DeviceFormFactor;
+import org.chromium.ui.base.WindowAndroid;
+
+import java.lang.reflect.Field;
+
+/**
+ * The main Chrome activity.  This exposes extra methods that relate to the {@link TabModelSelector}
+ * and lists of tabs.
+ */
+public abstract class ChromeActivity extends AsyncInitializationActivity implements
+        TabCreatorManager, AccessibilityStateChangeListener, PolicyChangeListener {
+
+    private static final String SNAPSHOT_DATABASE_REMOVED = "snapshot_database_removed";
+    private static final String SNAPSHOT_DATABASE_NAME = "snapshots.db";
+
+    /** Delay in ms after first page load finishes before we initiate deferred startup actions. */
+    private static final int DEFERRED_STARTUP_DELAY_MS = 1000;
+
+    /**
+     * Timeout in ms for reading PartnerBrowserCustomizations provider.
+     */
+    private static final int PARTNER_BROWSER_CUSTOMIZATIONS_TIMEOUT_MS = 10000;
+
+    private TabModelSelector mTabModelSelector;
+    private TabModelSelectorTabObserver mTabModelSelectorTabObserver;
+    private ChromeTabCreator mRegularTabCreator;
+    private ChromeTabCreator mIncognitoTabCreator;
+    private TabContentManager mTabContentManager;
+    private UmaSessionStats mUmaSessionStats;
+    private ContextReporter mContextReporter;
+    protected GSAServiceClient mGSAServiceClient;
+
+    private int mCurrentOrientation = Surface.ROTATION_0;
+    private boolean mPartnerBrowserRefreshNeeded = false;
+
+    protected IntentHandler mIntentHandler;
+    protected boolean mIsTablet = false;
+    private long mLastUserInteractionTime;
+
+    /** Whether onDeferredStartup() has been run. */
+    private boolean mDeferredStartupNotified;
+
+    // The class cannot implement TouchExplorationStateChangeListener,
+    // because it is only available for Build.VERSION_CODES.KITKAT and later.
+    // We have to instantiate the TouchExplorationStateChangeListner object in the code.
+    private TouchExplorationStateChangeListener mTouchExplorationStateChangeListener;
+
+    // Observes when sync becomes ready to create the mContextReporter.
+    private ProfileSyncService.SyncStateChangedListener mSyncStateChangedListener;
+
+    @SuppressLint("NewApi")
+    @Override
+    protected void onDestroy() {
+        getChromeApplication().removePolicyChangeListener(this);
+        if (mTabContentManager != null) mTabContentManager.destroy();
+        if (mTabModelSelectorTabObserver != null) mTabModelSelectorTabObserver.destroy();
+
+        AccessibilityManager manager = (AccessibilityManager)
+                getBaseContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
+        manager.removeAccessibilityStateChangeListener(this);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+            manager.removeTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
+        }
+
+        super.onDestroy();
+    }
+
+    /**
+     * {@link TabModelSelector} no longer implements TabModel.  Use getTabModelSelector() or
+     * getCurrentTabModel() depending on your needs.
+     * @return The {@link TabModelSelector}, possibly null.
+     */
+    public TabModelSelector getTabModelSelector() {
+        return mTabModelSelector;
+    }
+
+    /**
+     * Sets the {@link TabModelSelector} owned by this {@link ChromeActivity}.
+     * @param tabModelSelector A {@link TabModelSelector} instance.
+     */
+    protected void setTabModelSelector(TabModelSelector tabModelSelector) {
+        mTabModelSelector = tabModelSelector;
+
+        if (mTabModelSelectorTabObserver != null) mTabModelSelectorTabObserver.destroy();
+        mTabModelSelectorTabObserver = new TabModelSelectorTabObserver(tabModelSelector) {
+            @Override
+            public void onLoadStopped(Tab tab) {
+                postDeferredStartupIfNeeded();
+                showUpdateInfoBarIfNecessary();
+            }
+
+            @Override
+            public void onPageLoadFinished(Tab tab) {
+                postDeferredStartupIfNeeded();
+                showUpdateInfoBarIfNecessary();
+            }
+
+            @Override
+            public void onCrash(Tab tab, boolean sadTabShown) {
+                postDeferredStartupIfNeeded();
+            }
+        };
+    }
+
+    @Override
+    public ChromeTabCreator getTabCreator(boolean incognito) {
+        return incognito ? mIncognitoTabCreator : mRegularTabCreator;
+    }
+
+    /**
+     * Sets the {@link ChromeTabCreator}s owned by this {@link ChromeActivity}.
+     * @param regularTabCreator A {@link ChromeTabCreator} instance.
+     */
+    public void setTabCreators(ChromeTabCreator regularTabCreator,
+            ChromeTabCreator incognitoTabCreator) {
+        mRegularTabCreator = regularTabCreator;
+        mIncognitoTabCreator = incognitoTabCreator;
+    }
+
+    /**
+     * Convenience method that returns a tab creator for the currently selected {@link TabModel}.
+     * @return A tab creator for the currently selected {@link TabModel}.
+     */
+    public ChromeTabCreator getCurrentTabCreator() {
+        return getTabCreator(getTabModelSelector().isIncognitoSelected());
+    }
+
+    /**
+     * Gets the {@link TabContentManager} instance which holds snapshots of the tabs in this model.
+     * @return The thumbnail cache, possibly null.
+     */
+    public TabContentManager getTabContentManager() {
+        return mTabContentManager;
+    }
+
+    /**
+     * Sets the {@link TabContentManager} owned by this {@link ChromeActivity}.
+     * @param tabContentManager A {@link TabContentManager} instance.
+     */
+    protected void setTabContentManager(TabContentManager tabContentManager) {
+        mTabContentManager = tabContentManager;
+    }
+
+    /**
+     * Gets the current (inner) TabModel.  This is a convenience function for
+     * getModelSelector().getCurrentModel().  It is *not* equivalent to the former getModel()
+     * @return Never null, if modelSelector or its field is uninstantiated returns a
+     *         {@link EmptyTabModel} singleton
+     */
+    public TabModel getCurrentTabModel() {
+        TabModelSelector modelSelector = getTabModelSelector();
+        if (modelSelector == null) return EmptyTabModel.getInstance();
+        return modelSelector.getCurrentModel();
+    }
+
+    /**
+     * Returns the tab being displayed by this ChromeActivity instance. This allows differentiation
+     * between ChromeActivity subclasses that swap between multiple tabs (e.g. ChromeTabbedActivity)
+     * and subclasses that only display one Tab (e.g. FullScreenActivity and DocumentActivity).
+     *
+     * The default implementation grabs the tab currently selected by the TabModel, which may be
+     * null if the Tab does not exist or the system is not initialized.
+     */
+    public Tab getActivityTab() {
+        return TabModelUtils.getCurrentTab(getCurrentTabModel());
+    }
+
+    /**
+     * @return The current ContentViewCore, or null if the tab does not exist or is not showing a
+     *         ContentViewCore.
+     */
+    public ContentViewCore getCurrentContentViewCore() {
+        return TabModelUtils.getCurrentContentViewCore(getCurrentTabModel());
+    }
+
+    /**
+     * Gets the full screen manager.
+     * @return The fullscreen manager, possibly null
+     */
+    public FullscreenManager getFullscreenManager() {
+        return null;
+    }
+
+    /**
+     * @return The content offset provider, may be null.
+     */
+    public ContentOffsetProvider getContentOffsetProvider() {
+        return null;
+    }
+
+    /**
+     * @return The content readback handler, may be null.
+     */
+    public ContentReadbackHandler getContentReadbackHandler() {
+        return null;
+    }
+
+    @Override
+    public void preInflationStartup() {
+        super.preInflationStartup();
+        ApplicationInitialization.enableFullscreenFlags(
+                getResources(), this, getControlContainerHeightResource());
+        mIsTablet = DeviceFormFactor.isTablet(this);
+        getWindow().setBackgroundDrawableResource(R.color.light_background_color);
+    }
+
+    @SuppressLint("NewApi")
+    @Override
+    public void postInflationStartup() {
+        super.postInflationStartup();
+        // Low end device UI should be allowed only after a fresh install or when the data has
+        // been cleared. This must happen before anyone calls SysUtils.isLowEndDevice() or
+        // SysUtils.isLowEndDevice() will always return the wrong value.
+        if (OmahaClient.isFreshInstallOrDataHasBeenCleared(this)) {
+            ChromePreferenceManager.getInstance(this).setAllowLowEndDeviceUi();
+        }
+
+        if (!ChromePreferenceManager.getInstance(this).getAllowLowEndDeviceUi()) {
+            CommandLine.getInstance().appendSwitch(
+                    BaseSwitches.DISABLE_LOW_END_DEVICE_MODE);
+        }
+
+        AccessibilityManager manager = (AccessibilityManager)
+                getBaseContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
+        manager.addAccessibilityStateChangeListener(this);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+            mTouchExplorationStateChangeListener = new TouchExplorationStateChangeListener() {
+                @Override
+                public void onTouchExplorationStateChanged(boolean enabled) {
+                    checkAccessibility();
+                }
+            };
+            manager.addTouchExplorationStateChangeListener(mTouchExplorationStateChangeListener);
+        }
+    }
+
+    @Override
+    public void initializeCompositor() {
+        super.initializeCompositor();
+    }
+
+    @Override
+    public void initializeState() {
+        super.initializeState();
+        IntentHandler.setTestIntentsEnabled(
+                CommandLine.getInstance().hasSwitch(ContentSwitches.ENABLE_TEST_INTENTS));
+        mIntentHandler = new IntentHandler(createIntentHandlerDelegate(), getPackageName());
+    }
+
+    @Override
+    public void finishNativeInitialization() {
+        // Set up the initial orientation of the device.
+        checkOrientation();
+        findViewById(android.R.id.content).addOnLayoutChangeListener(
+                new View.OnLayoutChangeListener() {
+                    @Override
+                    public void onLayoutChange(View v, int left, int top, int right, int bottom,
+                            int oldLeft, int oldTop, int oldRight, int oldBottom) {
+                        checkOrientation();
+                    }
+                });
+
+        // Make the activity listen to policy change events
+        getChromeApplication().addPolicyChangeListener(this);
+
+        super.finishNativeInitialization();
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        if (mContextReporter != null) mContextReporter.enable();
+
+        if (mPartnerBrowserRefreshNeeded) {
+            mPartnerBrowserRefreshNeeded = false;
+            PartnerBrowserCustomizations.initializeAsync(getApplicationContext(),
+                    PARTNER_BROWSER_CUSTOMIZATIONS_TIMEOUT_MS);
+            PartnerBrowserCustomizations.setOnInitializeAsyncFinished(new Runnable() {
+                @Override
+                public void run() {
+                    if (PartnerBrowserCustomizations.isIncognitoDisabled()) {
+                        terminateIncognitoSession();
+                    }
+                }
+            });
+        }
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (mContextReporter != null) mContextReporter.disable();
+
+        // We want to refresh partner browser provider every onStart().
+        mPartnerBrowserRefreshNeeded = true;
+    }
+
+    @Override
+    public void onStartWithNative() {
+        super.onStartWithNative();
+        getChromeApplication().onStartWithNative();
+        Tab tab = getActivityTab();
+        if (tab != null) tab.onActivityStart();
+        FeatureUtilities.setDocumentModeEnabled(FeatureUtilities.isDocumentMode(this));
+        WarmupManager.getInstance().clearWebContentsIfNecessary();
+
+        if (GSAState.getInstance(this).isGsaAvailable()) {
+            mGSAServiceClient = new GSAServiceClient(this);
+            mGSAServiceClient.connect();
+            createContextReporterIfNeeded();
+        } else {
+            ContextReporter.reportStatus(ContextReporter.STATUS_GSA_NOT_AVAILABLE);
+        }
+    }
+
+    private void createContextReporterIfNeeded() {
+        if (mContextReporter != null || getActivityTab() == null) return;
+
+        final ProfileSyncService syncService = ProfileSyncService.get(this);
+
+        if (syncService.isSyncingUrlsWithKeystorePassphrase()) {
+            mContextReporter = ((ChromeMobileApplication) getApplicationContext()).createGsaHelper()
+                    .getContextReporter(this);
+
+            if (mSyncStateChangedListener != null) {
+                syncService.removeSyncStateChangedListener(mSyncStateChangedListener);
+                mSyncStateChangedListener = null;
+            }
+
+            return;
+        } else {
+            ContextReporter.reportSyncStatus(syncService);
+        }
+
+        if (mSyncStateChangedListener == null) {
+            mSyncStateChangedListener = new ProfileSyncService.SyncStateChangedListener() {
+                @Override
+                public void syncStateChanged() {
+                    createContextReporterIfNeeded();
+                }
+            };
+            syncService.addSyncStateChangedListener(mSyncStateChangedListener);
+        }
+    }
+
+    @Override
+    public void onResumeWithNative() {
+        super.onResumeWithNative();
+        markSessionResume();
+
+        if (getActivityTab() != null) {
+            LaunchMetrics.commitLaunchMetrics(getActivityTab().getWebContents());
+        }
+    }
+
+    @Override
+    public void onPauseWithNative() {
+        markSessionEnd();
+        super.onPauseWithNative();
+    }
+
+    @Override
+    public void onStopWithNative() {
+        if (mGSAServiceClient != null) {
+            mGSAServiceClient.disconnect();
+            mGSAServiceClient = null;
+            if (mSyncStateChangedListener != null) {
+                ProfileSyncService syncService = ProfileSyncService.get(this);
+                syncService.removeSyncStateChangedListener(mSyncStateChangedListener);
+                mSyncStateChangedListener = null;
+            }
+        }
+
+        super.onStopWithNative();
+    }
+
+    @Override
+    public void onNewIntentWithNative(Intent intent) {
+        super.onNewIntentWithNative(intent);
+        if (mIntentHandler.shouldIgnoreIntent(this, intent)) return;
+
+        mIntentHandler.onNewIntent(intent);
+    }
+
+    /**
+     * Called when the orientation of the device changes.  The orientation is checked/detected on
+     * root view layouts.
+     * @param orientation One of {@link Surface#ROTATION_0} (no rotation),
+     *                    {@link Surface#ROTATION_90}, {@link Surface#ROTATION_180}, or
+     *                    {@link Surface#ROTATION_270}.
+     */
+    protected void onOrientationChange(int orientation) {
+    }
+
+    /**
+     * Called when the accessibility status of this device changes.  This might be triggered by
+     * touch exploration or general accessibility status updates.  It is an aggregate of two other
+     * accessibility update methods.
+     * @see #onAccessibilityModeChanged(boolean)
+     * @see #onTouchExplorationStateChanged(boolean)
+     * @param enabled Whether or not accessibility and touch exploration are currently enabled.
+     */
+    protected void onAccessibilityModeChanged(boolean enabled) {
+        InfoBarContainer.setIsAllowedToAutoHide(!enabled);
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item != null && onMenuOrKeyboardAction(item.getItemId(), true)) {
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    public void onUserInteraction() {
+        mLastUserInteractionTime = SystemClock.elapsedRealtime();
+    }
+
+    /**
+     * Handles menu item selection and keyboard shortcuts.
+     *
+     * @param id The ID of the selected menu item (defined in main_menu.xml) or
+     *           keyboard shortcut (defined in values.xml).
+     * @param fromMenu Whether this was triggered from the menu.
+     * @return Whether the action was handled.
+     */
+    public boolean onMenuOrKeyboardAction(int id, boolean fromMenu) {
+        return false;
+    }
+
+    /**
+     * Triggered when the share menu item is selected.
+     * This creates and shows a share intent picker dialog or starts a share intent directly.
+     *
+     * @param currentTab The {@link Tab} a user is watching.
+     * @param windowAndroid The {@link WindowAndroid} currentTab is linked to.
+     * @param shareDirectly Whether it should share directly with the activity that was most
+     *                      recently used to share.
+     * @param isIncognito Whether currentTab is incognito.
+     */
+    public void onShareMenuItemSelected(final Tab currentTab,
+            final WindowAndroid windowAndroid, final boolean shareDirectly, boolean isIncognito) {
+        if (currentTab == null) return;
+
+        final Activity mainActivity = this;
+        ContentReadbackHandler.GetBitmapCallback bitmapCallback =
+                new ContentReadbackHandler.GetBitmapCallback() {
+                    @Override
+                    public void onFinishGetBitmap(Bitmap bitmap, int reponse) {
+                        ShareHelper.share(shareDirectly, mainActivity, currentTab.getTitle(),
+                                currentTab.getUrl(), bitmap);
+                        if (shareDirectly) {
+                            RecordUserAction.record("MobileMenuDirectShare");
+                        } else {
+                            RecordUserAction.record("MobileMenuShare");
+                        }
+                    }
+                };
+        ContentReadbackHandler readbackHandler = getContentReadbackHandler();
+        if (isIncognito || readbackHandler == null || windowAndroid == null
+                || currentTab.getContentViewCore() == null) {
+            bitmapCallback.onFinishGetBitmap(null, ReadbackResponse.SURFACE_UNAVAILABLE);
+        } else {
+            readbackHandler.getContentBitmapAsync(1, new Rect(), currentTab.getContentViewCore(),
+                    Bitmap.Config.ARGB_8888, bitmapCallback);
+        }
+    }
+
+    /**
+     * @return Whether the activity is running in tablet mode.
+     */
+    public boolean isTablet() {
+        return mIsTablet;
+    }
+
+    /**
+     * @return Whether the activity is in overview mode.
+     */
+    public boolean isInOverviewMode() {
+        return false;
+    }
+
+    /**
+     * @return Whether the app menu should be shown.
+     */
+    public boolean shouldShowAppMenu() {
+        return false;
+    }
+
+    /**
+     * Allows Activities that extend ChromeActivity to do additional hiding/showing of menu items.
+     * @param menu Menu that is going to be shown when the menu button is pressed.
+     */
+    public void prepareMenu(Menu menu) {
+    }
+
+    /**
+     * @return timestamp when the last user interaction was made.
+     */
+    public long getLastUserInteractionTime() {
+        return mLastUserInteractionTime;
+    }
+
+    protected IntentHandlerDelegate createIntentHandlerDelegate() {
+        return new IntentHandlerDelegate() {
+            @Override
+            public void processWebSearchIntent(String query) {
+                Intent searchIntent = new Intent(Intent.ACTION_WEB_SEARCH);
+                searchIntent.putExtra(SearchManager.QUERY, query);
+                startActivity(searchIntent);
+            }
+
+            @Override
+            public void processUrlViewIntent(String url, String headers, TabOpenType tabOpenType,
+                    String externalAppId, int tabIdToBringToFront, Intent intent) {
+            }
+        };
+    }
+
+    /**
+     * @return The resource id that contains how large the top controls are.
+     */
+    protected int getControlContainerHeightResource() {
+        return R.dimen.control_container_height;
+    }
+
+    private void markSessionResume() {
+        // Start new session for UMA.
+        if (mUmaSessionStats == null) {
+            mUmaSessionStats = new UmaSessionStats(this);
+        }
+
+        mUmaSessionStats.updateMetricsServiceState();
+        // In DocumentMode we need the application-level TabModelSelector instead of per
+        // activity which only manages a single tab.
+        if (FeatureUtilities.isDocumentMode(this)) {
+            mUmaSessionStats.startNewSession(
+                    ChromeMobileApplication.getDocumentTabModelSelector());
+        } else {
+            mUmaSessionStats.startNewSession(getTabModelSelector());
+        }
+    }
+
+    /**
+     * Mark that the UMA session has ended.
+     */
+    private void markSessionEnd() {
+        if (mUmaSessionStats == null) {
+            // If you hit this assert, please update crbug.com/172653 on how you got there.
+            assert false;
+            return;
+        }
+        // Record session metrics.
+        mUmaSessionStats.logMultiWindowStats(windowArea(), displayArea(),
+                TabWindowManager.getInstance().getNumberOfAssignedTabModelSelectors());
+        mUmaSessionStats.logAndEndSession();
+    }
+
+    private int windowArea() {
+        Window window = getWindow();
+        if (window != null) {
+            View view =  window.getDecorView();
+            return view.getWidth() * view.getHeight();
+        }
+        return -1;
+    }
+
+    private int displayArea() {
+        if (getResources() != null && getResources().getDisplayMetrics() != null) {
+            DisplayMetrics metrics = getResources().getDisplayMetrics();
+            return metrics.heightPixels * metrics.widthPixels;
+        }
+        return -1;
+    }
+
+    @Override
+    public final void onAccessibilityStateChanged(boolean enabled) {
+        checkAccessibility();
+    }
+
+    private void checkAccessibility() {
+        onAccessibilityModeChanged(DeviceClassManager.isAccessibilityModeEnabled(this));
+    }
+
+    private void checkOrientation() {
+        WindowManager wm = getWindowManager();
+        if (wm == null) return;
+
+        Display display = wm.getDefaultDisplay();
+        if (display == null) return;
+
+        int oldOrientation = mCurrentOrientation;
+        mCurrentOrientation = display.getRotation();
+
+        if (oldOrientation != mCurrentOrientation) onOrientationChange(mCurrentOrientation);
+    }
+
+    /**
+     * Removes the window background.
+     */
+    protected void removeWindowBackground() {
+        boolean removeWindowBackground = true;
+        try {
+            Field field = Settings.Secure.class.getField(
+                    "ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED");
+            field.setAccessible(true);
+
+            if (field.getType() == String.class) {
+                String accessibilityMagnificationSetting = (String) field.get(null);
+                // When Accessibility magnification is turned on, setting a null window
+                // background causes the overlaid android views to stretch when panning.
+                // (crbug/332994)
+                if (Settings.Secure.getInt(
+                        getContentResolver(), accessibilityMagnificationSetting) == 1) {
+                    removeWindowBackground = false;
+                }
+            }
+        } catch (SettingNotFoundException e) {
+            // Window background is removed if an exception occurs.
+        } catch (NoSuchFieldException e) {
+            // Window background is removed if an exception occurs.
+        } catch (IllegalAccessException e) {
+            // Window background is removed if an exception occurs.
+        } catch (IllegalArgumentException e) {
+            // Window background is removed if an exception occurs.
+        }
+        if (removeWindowBackground) getWindow().setBackgroundDrawable(null);
+    }
+
+    /**
+     * @return A casted version of {@link #getApplication()}.
+     */
+    public ChromeMobileApplication getChromeApplication() {
+        return (ChromeMobileApplication) getApplication();
+    }
+
+    /**
+     * @return Whether the update infobar may be shown.
+     */
+    public boolean mayShowUpdateInfoBar() {
+        return true;
+    }
+
+    /**
+     * Actions that may be run at some point after startup. Place tasks that are not critical to the
+     * startup path here.  This method will be called automatically and should not be called
+     * directly by subclasses.  Overriding methods should call super.onDeferredStartup().
+     */
+    protected void onDeferredStartup() {
+        boolean crashDumpUploadingDisabled = getIntent() != null
+                && getIntent().hasExtra(
+                        ChromeTabbedActivity.INTENT_EXTRA_DISABLE_CRASH_DUMP_UPLOADING);
+        DeferredStartupHandler.getInstance()
+                .onDeferredStartup(getChromeApplication(), crashDumpUploadingDisabled);
+
+        BeamController.registerForBeam(this, new BeamProvider() {
+            @Override
+            public String getTabUrlForBeam() {
+                if (isOverlayVisible()) return null;
+                if (getActivityTab() == null) return null;
+                return getActivityTab().getUrl();
+            }
+        });
+
+        getChromeApplication().getUpdateInfoBarHelper().checkForUpdateOnBackgroundThread(this);
+        removeSnapshotDatabase();
+    }
+
+    private void postDeferredStartupIfNeeded() {
+        if (!mDeferredStartupNotified) {
+            // We want to perform deferred startup tasks a short time after the first page
+            // load completes, but only when the main thread Looper has become idle.
+            mHandler.postDelayed(new Runnable() {
+                @Override
+                public void run() {
+                    if (!mDeferredStartupNotified && !isActivityDestroyed()) {
+                        mDeferredStartupNotified = true;
+                        Looper.myQueue().addIdleHandler(new MessageQueue.IdleHandler() {
+                            @Override
+                            public boolean queueIdle() {
+                                onDeferredStartup();
+                                return false;  // Remove this idle handler.
+                            }
+                        });
+                    }
+                }
+            }, DEFERRED_STARTUP_DELAY_MS);
+        }
+    }
+
+    private void showUpdateInfoBarIfNecessary() {
+        getChromeApplication().getUpdateInfoBarHelper().showUpdateInfobarIfNecessary(this);
+    }
+
+    /**
+     * Determines whether the ContentView is currently visible and not hidden by an overlay
+     * @return true if the ContentView is fully hidden by another view (i.e. the tab stack)
+     */
+    public boolean isOverlayVisible() {
+        return false;
+    }
+
+    /**
+     * Deletes the snapshot database which is no longer used because the feature has been removed
+     * in Chrome M41.
+     */
+    private void removeSnapshotDatabase() {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+        if (!prefs.getBoolean(SNAPSHOT_DATABASE_REMOVED, false)) {
+            deleteDatabase(SNAPSHOT_DATABASE_NAME);
+            prefs.edit().putBoolean(SNAPSHOT_DATABASE_REMOVED, true).apply();
+        }
+    }
+
+    @Override
+    public void terminateIncognitoSession() {}
+
+    /**
+     * @return The {@code ContextualSearchManager} or {@code null} if none;
+     */
+    public ContextualSearchManager getContextualSearchManager() {
+        return null;
+    }
+}