Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/tab/ChromeTab.java

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/tab/ChromeTab.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/tab/ChromeTab.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/tab/ChromeTab.java
new file mode 100644
index 0000000000000000000000000000000000000000..0aca3d8a199e4050c46b8981c05bb0284cf9dc30
--- /dev/null
+++ b/chrome/android/java_staging/src/org/chromium/chrome/browser/tab/ChromeTab.java
@@ -0,0 +1,1388 @@
+// 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.tab;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Rect;
+import android.media.AudioManager;
+import android.os.Build;
+import android.os.Handler;
+import android.os.Message;
+import android.text.TextUtils;
+import android.view.ActionMode;
+import android.view.ContextMenu;
+import android.view.KeyEvent;
+import android.view.View;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.base.Log;
+import org.chromium.base.TraceEvent;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.metrics.RecordUserAction;
+import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.ChromeMobileApplication;
+import org.chromium.chrome.browser.CompositorChromeActivity;
+import org.chromium.chrome.browser.EmptyTabObserver;
+import org.chromium.chrome.browser.FrozenNativePage;
+import org.chromium.chrome.browser.IntentHandler.TabOpenType;
+import org.chromium.chrome.browser.NativePage;
+import org.chromium.chrome.browser.Tab;
+import org.chromium.chrome.browser.TabObserver;
+import org.chromium.chrome.browser.TabState;
+import org.chromium.chrome.browser.TabUma;
+import org.chromium.chrome.browser.TabUma.TabCreationState;
+import org.chromium.chrome.browser.contextmenu.ChromeContextMenuPopulator;
+import org.chromium.chrome.browser.contextmenu.ContextMenuParams;
+import org.chromium.chrome.browser.contextmenu.ContextMenuPopulator;
+import org.chromium.chrome.browser.contextualsearch.ContextualSearchTabHelper;
+import org.chromium.chrome.browser.crash.MinidumpUploadService;
+import org.chromium.chrome.browser.dom_distiller.ReaderModeActivityDelegate;
+import org.chromium.chrome.browser.dom_distiller.ReaderModeManager;
+import org.chromium.chrome.browser.download.ChromeDownloadDelegate;
+import org.chromium.chrome.browser.externalnav.ExternalNavigationHandler;
+import org.chromium.chrome.browser.externalnav.ExternalNavigationHandler.OverrideUrlLoadingResult;
+import org.chromium.chrome.browser.externalnav.ExternalNavigationParams;
+import org.chromium.chrome.browser.fullscreen.FullscreenManager;
+import org.chromium.chrome.browser.media.MediaNotificationService;
+import org.chromium.chrome.browser.net.spdyproxy.DataReductionProxySettings;
+import org.chromium.chrome.browser.ntp.NativePageAssassin;
+import org.chromium.chrome.browser.ntp.NativePageFactory;
+import org.chromium.chrome.browser.omnibox.geo.GeolocationHeader;
+import org.chromium.chrome.browser.policy.PolicyAuditor;
+import org.chromium.chrome.browser.policy.PolicyAuditor.AuditEvent;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge;
+import org.chromium.chrome.browser.rlz.RevenueStats;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService;
+import org.chromium.chrome.browser.tab.BackgroundContentViewHelper.BackgroundContentViewDelegate;
+import org.chromium.chrome.browser.tabmodel.TabModel;
+import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
+import org.chromium.chrome.browser.tabmodel.TabModel.TabSelectionType;
+import org.chromium.chrome.browser.tabmodel.TabModelUtils;
+import org.chromium.components.dom_distiller.core.DomDistillerUrlUtils;
+import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
+import org.chromium.components.navigation_interception.NavigationParams;
+import org.chromium.content.browser.ActivityContentVideoViewClient;
+import org.chromium.content.browser.ContentVideoViewClient;
+import org.chromium.content.browser.ContentViewClient;
+import org.chromium.content.browser.ContentViewCore;
+import org.chromium.content.browser.SelectActionMode;
+import org.chromium.content.browser.SelectActionModeCallback.ActionHandler;
+import org.chromium.content.browser.crypto.CipherFactory;
+import org.chromium.content_public.browser.GestureStateListener;
+import org.chromium.content_public.browser.InvalidateTypes;
+import org.chromium.content_public.browser.LoadUrlParams;
+import org.chromium.content_public.browser.NavigationController;
+import org.chromium.content_public.browser.WebContents;
+import org.chromium.content_public.browser.WebContentsObserver;
+import org.chromium.content_public.common.ConsoleMessageLevel;
+import org.chromium.content_public.common.Referrer;
+import org.chromium.ui.WindowOpenDisposition;
+import org.chromium.ui.base.PageTransition;
+import org.chromium.ui.base.WindowAndroid;
+
+import java.util.Locale;
+
+/**
+ * A representation of a Tab for Chrome. This manages wrapping a WebContents and interacting with
+ * most of Chromium while representing a consistent version of web content to the front end.
+ */
+public class ChromeTab extends Tab {
+    public static final int NTP_TAB_ID = -2;
+
+    private static final String TAG = "ChromeTab";
+
+    // URL didFailLoad error code. Should match the value in net_error_list.h.
+    public static final int BLOCKED_BY_ADMINISTRATOR = -22;
+
+    public static final String PAGESPEED_PASSTHROUGH_HEADER =
+            "X-PSA-Client-Options: v=1,m=1\nCache-Control: no-cache";
+
+    private static final int MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD = 1;
+
+    /** The maximum amount of time to wait for a page to load before entering fullscreen.  -1 means
+     *  wait until the page finishes loading. */
+    private static final long MAX_FULLSCREEN_LOAD_DELAY_MS = 3000;
+
+    private ReaderModeManager mReaderModeManager;
+
+    private TabRedirectHandler mTabRedirectHandler;
+
+    private ChromeDownloadDelegate mDownloadDelegate;
+
+    private boolean mIsFullscreenWaitingForLoad = false;
+    private ExternalNavigationHandler.OverrideUrlLoadingResult mLastOverrideUrlLoadingResult =
+            ExternalNavigationHandler.OverrideUrlLoadingResult.NO_OVERRIDE;
+
+    /**
+     * Whether didCommitProvisionalLoadForFrame() hasn't yet been called for the current native page
+     * (page A). To decrease latency, we show native pages in both loadUrl() and
+     * didCommitProvisionalLoadForFrame(). However, we mustn't show a new native page (page B) in
+     * loadUrl() if the current native page hasn't yet been committed. Otherwise, we'll show each
+     * page twice (A, B, A, B): the first two times in loadUrl(), the second two times in
+     * didCommitProvisionalLoadForFrame().
+     */
+    private boolean mIsNativePageCommitPending;
+
+    protected final ChromeActivity mActivity;
+
+    private WebContentsObserver mWebContentsObserver;
+
+    private Handler mHandler;
+
+    private final Runnable mCloseContentsRunnable = new Runnable() {
+        @Override
+        public void run() {
+            mActivity.getTabModelSelector().closeTab(ChromeTab.this);
+        }
+    };
+
+    /**
+     * The data reduction proxy was in use on the last page load if true.
+     */
+    protected boolean mUsedSpdyProxy;
+
+    /**
+     * The data reduction proxy was in pass through mode on the last page load if true.
+     */
+    protected boolean mUsedSpdyProxyWithPassthrough;
+
+    /**
+     * The last page load had request headers indicating that the data reduction proxy should
+     * be put in pass through mode, if true.
+     */
+    private boolean mLastPageLoadHasSpdyProxyPassthroughHeaders;
+
+    /**
+     * Listens to gesture events fired by the ContentViewCore.
+     */
+    private GestureStateListener mGestureStateListener;
+
+    /**
+     * The background content view helper which loads the original page in background content view.
+     */
+    private BackgroundContentViewHelper mBackgroundContentViewHelper;
+
+    /**
+     * The load progress of swapped in content view at the time of swap.
+     */
+    private int mLoadProgressAtViewSwapInTime;
+
+    /**
+     * Whether forward history should be cleared after navigation is committed.
+     */
+    private boolean mClearAllForwardHistoryRequired;
+
+    private boolean mShouldClearRedirectHistoryForTabClobbering;
+
+    /**
+     * Basic constructor. This is hidden, so that explicitly named factory methods are used to
+     * create tabs. initialize() needs to be called afterwards to complete the second level
+     * initialization.
+     * @param creationState State in which the tab is created, needed to initialize TabUma
+     *                      accounting. When null, TabUma will not be initialized.
+     * @param frozenState TabState that was saved when the Tab was last persisted to storage.
+     */
+    protected ChromeTab(
+            int id, ChromeActivity activity, boolean incognito, WindowAndroid nativeWindow,
+            TabLaunchType type, int parentId, TabCreationState creationState,
+            TabState frozenState) {
+        super(id, parentId, incognito, activity, nativeWindow, type, frozenState);
+
+        if (frozenState == null) {
+            assert type != TabLaunchType.FROM_RESTORE
+                    && creationState != TabCreationState.FROZEN_ON_RESTORE;
+        } else {
+            assert type == TabLaunchType.FROM_RESTORE
+                    && creationState == TabCreationState.FROZEN_ON_RESTORE;
+        }
+
+        addObserver(mTabObserver);
+        mActivity = activity;
+        mHandler = new Handler() {
+            @Override
+            public void handleMessage(Message msg) {
+                if (msg == null) return;
+                if (msg.what == MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD) {
+                    enableFullscreenAfterLoad();
+                }
+            }
+        };
+        setContentViewClient(createContentViewClient());
+        if (mActivity != null && creationState != null) {
+            setTabUma(new TabUma(
+                    this, creationState, mActivity.getTabModelSelector().getModel(incognito)));
+        }
+
+        if (incognito) {
+            CipherFactory.getInstance().triggerKeyGeneration();
+        }
+
+        mReaderModeManager = new ReaderModeManager(this, activity);
+        RevenueStats.getInstance().tabCreated(this);
+
+        mTabRedirectHandler = new TabRedirectHandler(activity);
+
+        ContextualSearchTabHelper.createForTab(this);
+        if (nativeWindow != null) ThumbnailTabHelper.createForTab(this);
+    }
+
+    /**
+     * Creates a minimal {@link ChromeTab} for testing. Do not use outside testing.
+     *
+     * @param id        The id of the tab.
+     * @param incognito Whether the tab is incognito.
+     */
+    @VisibleForTesting
+    public ChromeTab(int id, boolean incognito) {
+        super(id, incognito, null, null);
+        mActivity = null;
+        mTabRedirectHandler = new TabRedirectHandler(null);
+    }
+
+    /**
+     * Creates a fresh tab. initialize() needs to be called afterwards to complete the second level
+     * initialization.
+     * @param initiallyHidden true iff the tab being created is initially in background
+     */
+    public static ChromeTab createLiveTab(int id, ChromeActivity activity, boolean incognito,
+            WindowAndroid nativeWindow, TabLaunchType type, int parentId, boolean initiallyHidden) {
+        return new ChromeTab(id, activity, incognito, nativeWindow, type, parentId,
+                initiallyHidden ? TabCreationState.LIVE_IN_BACKGROUND :
+                                  TabCreationState.LIVE_IN_FOREGROUND, null);
+    }
+
+    /**
+     * Creates a new, "frozen" tab from a saved state. This can be used for background tabs restored
+     * on cold start that should be loaded when switched to. initialize() needs to be called
+     * afterwards to complete the second level initialization.
+     */
+    public static ChromeTab createFrozenTabFromState(
+            int id, ChromeActivity activity, boolean incognito,
+            WindowAndroid nativeWindow, int parentId, TabState state) {
+        assert state != null;
+        return new ChromeTab(id, activity, incognito, nativeWindow,
+                TabLaunchType.FROM_RESTORE, parentId, TabCreationState.FROZEN_ON_RESTORE,
+                state);
+    }
+
+    /**
+     * Creates a new tab to be loaded lazily. This can be used for tabs opened in the background
+     * that should be loaded when switched to. initialize() needs to be called afterwards to
+     * complete the second level initialization.
+     */
+    public static ChromeTab createTabForLazyLoad(ChromeActivity activity, boolean incognito,
+            WindowAndroid nativeWindow, TabLaunchType type, int parentId,
+            LoadUrlParams loadUrlParams) {
+        ChromeTab tab = new ChromeTab(
+                INVALID_TAB_ID, activity, incognito, nativeWindow, type, parentId,
+                TabCreationState.FROZEN_FOR_LAZY_LOAD, null);
+        tab.setPendingLoadParams(loadUrlParams);
+        return tab;
+    }
+
+    public static ChromeTab fromTab(Tab tab) {
+        return (ChromeTab) tab;
+    }
+
+    /**
+     * Initializes the ChromeTab after construction with an existing ContentViewCore.
+     */
+    @Override
+    protected void internalInit() {
+        super.internalInit();
+        if (mBackgroundContentViewHelper == null) {
+            BackgroundContentViewDelegate delegate = new BackgroundContentViewDelegate() {
+                @Override
+                public void onBackgroundViewReady(
+                        ContentViewCore cvc, boolean didStartLoad, boolean didFinishLoad,
+                        int progress) {
+                    WebContents previewWebContents = getWebContents();
+                    swapContentViewCore(cvc, false, didStartLoad, didFinishLoad);
+                    mLoadProgressAtViewSwapInTime = progress;
+                    mBackgroundContentViewHelper.unloadAndDeleteWebContents(previewWebContents);
+
+                    // Enter to fullscreen.
+                    mHandler.removeMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD);
+                    mHandler.sendEmptyMessageDelayed(
+                            MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD, MAX_FULLSCREEN_LOAD_DELAY_MS);
+                    updateFullscreenEnabledState();
+                }
+
+                @Override
+                public void onLoadProgressChanged(int progress) {
+                    notifyLoadProgress(getProgress());
+                }
+            };
+            mBackgroundContentViewHelper = new BackgroundContentViewHelper(
+                    getWindowAndroid(), this, delegate);
+        }
+    }
+
+    /**
+     * Remember if the last load used the data reduction proxy, and if so,
+     * also remember if it used pass through mode.
+     */
+    private void maybeSetDataReductionProxyUsed() {
+        // Ignore internal URLs.
+        String url = getUrl();
+        if (url != null && url.toLowerCase(Locale.US).startsWith("chrome://")) {
+            return;
+        }
+        mUsedSpdyProxy = false;
+        mUsedSpdyProxyWithPassthrough = false;
+        if (isSpdyProxyEnabledForUrl(url)) {
+            mUsedSpdyProxy = true;
+            if (mLastPageLoadHasSpdyProxyPassthroughHeaders) {
+                mLastPageLoadHasSpdyProxyPassthroughHeaders = false;
+                mUsedSpdyProxyWithPassthrough = true;
+            }
+        }
+    }
+
+    @Override
+    protected void openNewTab(
+            LoadUrlParams params, TabLaunchType launchType, Tab parentTab, boolean incognito) {
+        mActivity.getTabModelSelector().openNewTab(params, launchType, parentTab, incognito);
+    }
+
+    @Override
+    protected TabChromeWebContentsDelegateAndroid createWebContentsDelegate() {
+        return new TabChromeWebContentsDelegateAndroidImpl();
+    }
+
+    /**
+     * An implementation for this tab's web contents delegate.
+     */
+    public class TabChromeWebContentsDelegateAndroidImpl
+            extends TabChromeWebContentsDelegateAndroid {
+        /**
+         * This method is meant to be overridden by DocumentTab because the
+         * TabModelSelector returned by the activity is not correct.
+         * TODO(dfalcantara): remove this when DocumentActivity.getTabModelSelector()
+         * will return the right TabModelSelector.
+         */
+        protected TabModel getTabModel() {
+            return mActivity.getTabModelSelector().getModel(isIncognito());
+        }
+
+        @Override
+        public boolean addNewContents(WebContents sourceWebContents, WebContents webContents,
+                int disposition, Rect initialPosition, boolean userGesture) {
+            if (isClosing()) return false;
+
+            // TODO(johnme): Open tabs in same order as Chrome.
+            Tab tab = mActivity.getTabCreator(isIncognito()).createTabWithWebContents(
+                    webContents, getId(), TabLaunchType.FROM_LONGPRESS_FOREGROUND);
+
+            if (tab == null) return false;
+
+            if (disposition == WindowOpenDisposition.NEW_POPUP) {
+                PolicyAuditor auditor =
+                        ((ChromeMobileApplication) getApplicationContext()).getPolicyAuditor();
+                auditor.notifyAuditEvent(getApplicationContext(), AuditEvent.OPEN_POPUP_URL_SUCCESS,
+                        tab.getUrl(), "");
+            }
+
+            return true;
+        }
+
+        @Override
+        public void activateContents() {
+            boolean activityIsDestroyed = false;
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+                activityIsDestroyed = mActivity.isDestroyed();
+            }
+            if (activityIsDestroyed || !isInitialized()) {
+                Log.e(TAG, "Activity destroyed before calling activateContents().  Bailing out.");
+                return;
+            }
+
+            TabModel model = getTabModel();
+            int index = model.indexOf(ChromeTab.this);
+            if (index == TabModel.INVALID_TAB_INDEX) return;
+
+            TabModelUtils.setIndex(model, index);
+
+            // This intent is sent in order to get the activity back to the foreground if it was
+            // not already. The previous call will activate the right tab in the context of the
+            // TabModel but will only show the tab to the user if Chrome was already in the
+            // foreground.
+            // The intent is getting the tabId mostly because it does not cost much to do so.
+            // When receiving the intent, the tab associated with the tabId should already be
+            // active.
+            // Note that calling only the intent in order to activate the tab is slightly slower
+            // because it will change the tab when the intent is handled, which happens after
+            // Chrome gets back to the foreground.
+            Intent newIntent = new Intent();
+            newIntent.setAction(Intent.ACTION_MAIN);
+            newIntent.setPackage(mActivity.getPackageName());
+            newIntent.putExtra(TabOpenType.BRING_TAB_TO_FRONT.name(),
+                               ChromeTab.this.getId());
+
+            newIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+            getApplicationContext().startActivity(newIntent);
+        }
+
+        @Override
+        public void navigationStateChanged(int flags) {
+            if ((flags & InvalidateTypes.TAB) != 0) {
+                MediaNotificationService.updateMediaNotificationForTab(
+                        getApplicationContext(), getId(), isCapturingAudio(),
+                        isCapturingVideo(), hasAudibleAudio(), getUrl());
+            }
+            super.navigationStateChanged(flags);
+        }
+
+        @Override
+        public void onLoadProgressChanged(int progress) {
+            if (!isLoading()) return;
+            if (progress >= mLoadProgressAtViewSwapInTime) mLoadProgressAtViewSwapInTime = 0;
+            notifyLoadProgress(getProgress());
+        }
+
+        @Override
+        public void closeContents() {
+            // Execute outside of callback, otherwise we end up deleting the native
+            // objects in the middle of executing methods on them.
+            mHandler.removeCallbacks(mCloseContentsRunnable);
+            mHandler.post(mCloseContentsRunnable);
+        }
+
+        @Override
+        public boolean takeFocus(boolean reverse) {
+            if (reverse) {
+                View menuButton = mActivity.findViewById(R.id.menu_button);
+                if (menuButton == null || !menuButton.isShown()) {
+                    menuButton = mActivity.findViewById(R.id.document_menu_button);
+                }
+                if (menuButton != null && menuButton.isShown()) {
+                    return menuButton.requestFocus();
+                }
+
+                View tabSwitcherButton = mActivity.findViewById(R.id.tab_switcher_button);
+                if (tabSwitcherButton != null && tabSwitcherButton.isShown()) {
+                    return tabSwitcherButton.requestFocus();
+                }
+            } else {
+                View urlBar = mActivity.findViewById(R.id.url_bar);
+                if (urlBar != null) return urlBar.requestFocus();
+            }
+            return false;
+        }
+
+        @Override
+        public void handleKeyboardEvent(KeyEvent event) {
+            if (event.getAction() == KeyEvent.ACTION_DOWN) {
+                if (mActivity.onKeyDown(event.getKeyCode(), event)) return;
+
+                // Handle the Escape key here (instead of in KeyboardShortcuts.java), so it doesn't
+                // interfere with other parts of the activity (e.g. the URL bar).
+                if (event.getKeyCode() == KeyEvent.KEYCODE_ESCAPE && event.hasNoModifiers()) {
+                    WebContents wc = getWebContents();
+                    if (wc != null) wc.stop();
+                    return;
+                }
+            }
+            handleMediaKey(event);
+        }
+
+        /**
+         * Redispatches unhandled media keys. This allows bluetooth headphones with play/pause or
+         * other buttons to function correctly.
+         */
+        @TargetApi(19)
+        private void handleMediaKey(KeyEvent e) {
+            if (Build.VERSION.SDK_INT < 19) return;
+            switch (e.getKeyCode()) {
+                case KeyEvent.KEYCODE_MUTE:
+                case KeyEvent.KEYCODE_HEADSETHOOK:
+                case KeyEvent.KEYCODE_MEDIA_PLAY:
+                case KeyEvent.KEYCODE_MEDIA_PAUSE:
+                case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
+                case KeyEvent.KEYCODE_MEDIA_STOP:
+                case KeyEvent.KEYCODE_MEDIA_NEXT:
+                case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
+                case KeyEvent.KEYCODE_MEDIA_REWIND:
+                case KeyEvent.KEYCODE_MEDIA_RECORD:
+                case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
+                case KeyEvent.KEYCODE_MEDIA_CLOSE:
+                case KeyEvent.KEYCODE_MEDIA_EJECT:
+                case KeyEvent.KEYCODE_MEDIA_AUDIO_TRACK:
+                    AudioManager am = (AudioManager) mActivity.getSystemService(
+                            Context.AUDIO_SERVICE);
+                    am.dispatchMediaKeyEvent(e);
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        /**
+         * @return Whether audio is being captured.
+         */
+        private boolean isCapturingAudio() {
+            return !isClosing() && super.nativeIsCapturingAudio(getWebContents());
+        }
+
+        /**
+         * @return Whether video is being captured.
+         */
+        private boolean isCapturingVideo() {
+            return !isClosing() && super.nativeIsCapturingVideo(getWebContents());
+        }
+
+        /**
+         * @return Whether audio is being played.
+         */
+        private boolean hasAudibleAudio() {
+            return !isClosing() && super.nativeHasAudibleAudio(getWebContents());
+        }
+
+    }
+
+    /**
+     * Check whether the context menu download should be intercepted.
+     *
+     * @param url URL to be downloaded.
+     * @return whether the download should be intercepted.
+     */
+    protected boolean shouldInterceptContextMenuDownload(String url) {
+        return mDownloadDelegate.shouldInterceptContextMenuDownload(url);
+    }
+
+    private class ChromeTabChromeContextMenuItemDelegate extends TabChromeContextMenuItemDelegate {
+        private boolean mIsImage;
+        private boolean mIsVideo;
+
+        public void setParamsInfo(boolean isImage, boolean isVideo) {
+            mIsImage = isImage;
+            mIsVideo = isVideo;
+        }
+
+        @Override
+        public boolean isIncognitoSupported() {
+            return PrefServiceBridge.getInstance().isIncognitoModeEnabled();
+        }
+
+        @Override
+        public boolean canLoadOriginalImage() {
+            return mUsedSpdyProxy && !mUsedSpdyProxyWithPassthrough;
+        }
+
+        @Override
+        public boolean startDownload(String url, boolean isLink) {
+            if (isLink) {
+                RecordUserAction.record("MobileContextMenuDownloadLink");
+                if (shouldInterceptContextMenuDownload(url)) {
+                    return false;
+                }
+            } else if (mIsImage) {
+                RecordUserAction.record("MobileContextMenuDownloadImage");
+            } else if (mIsVideo) {
+                RecordUserAction.record("MobileContextMenuDownloadVideo");
+            }
+            return true;
+        }
+
+        @Override
+        public void onSaveToClipboard(String text, boolean isUrl) {
+            if (isUrl) {
+                RecordUserAction.record("MobileContextMenuCopyLinkAddress");
+            } else {
+                RecordUserAction.record("MobileContextMenuCopyLinkText");
+            }
+            super.onSaveToClipboard(text, isUrl);
+        }
+
+        @Override
+        public void onSaveImageToClipboard(String url) {
+            RecordUserAction.record("MobileContextMenuSaveImage");
+            super.onSaveImageToClipboard(url);
+        }
+
+        @Override
+        public void onOpenInNewTab(String url, Referrer referrer) {
+            RecordUserAction.record("MobileContextMenuOpenLinkInNewTab");
+            RecordUserAction.record("MobileNewTabOpened");
+            LoadUrlParams loadUrlParams = new LoadUrlParams(url);
+            loadUrlParams.setReferrer(referrer);
+            mActivity.getTabModelSelector().openNewTab(loadUrlParams,
+                    TabLaunchType.FROM_LONGPRESS_BACKGROUND, ChromeTab.this, isIncognito());
+        }
+
+        @Override
+        public void onOpenInNewIncognitoTab(String url) {
+            RecordUserAction.record("MobileContextMenuOpenLinkInIncognito");
+            RecordUserAction.record("MobileNewTabOpened");
+            mActivity.getTabModelSelector().openNewTab(new LoadUrlParams(url),
+                    TabLaunchType.FROM_LONGPRESS_FOREGROUND, ChromeTab.this, true);
+        }
+
+        @Override
+        public void onOpenImageUrl(String url, Referrer referrer) {
+            RecordUserAction.record("MobileContextMenuViewImage");
+            super.onOpenImageUrl(url, referrer);
+        }
+
+        @Override
+        public void onOpenImageInNewTab(String url, Referrer referrer) {
+            boolean useOriginal = isSpdyProxyEnabledForUrl(url);
+            RecordUserAction.record("MobileContextMenuOpenImageInNewTab");
+            if (useOriginal) {
+                RecordUserAction.record("MobileContextMenuOpenOriginalImageInNewTab");
+            }
+
+            LoadUrlParams loadUrlParams = new LoadUrlParams(url);
+            loadUrlParams.setVerbatimHeaders(useOriginal ? PAGESPEED_PASSTHROUGH_HEADER : null);
+            loadUrlParams.setReferrer(referrer);
+            mActivity.getTabModelSelector().openNewTab(loadUrlParams,
+                    TabLaunchType.FROM_LONGPRESS_BACKGROUND, ChromeTab.this, isIncognito());
+        }
+
+        @Override
+        public void onSearchByImageInNewTab() {
+            RecordUserAction.record("MobileContextMenuSearchByImage");
+            super.onSearchByImageInNewTab();
+        }
+    }
+
+    /**
+     * This class is solely to track UMA stats.  When we upstream UMA stats we can remove this.
+     */
+    private static class ChromeTabChromeContextMenuPopulator extends ChromeContextMenuPopulator {
+        private final ChromeTabChromeContextMenuItemDelegate mDelegate;
+
+        public ChromeTabChromeContextMenuPopulator(
+                ChromeTabChromeContextMenuItemDelegate delegate) {
+            super(delegate);
+
+            mDelegate = delegate;
+        }
+
+        @Override
+        public void buildContextMenu(ContextMenu menu, Context context,
+                ContextMenuParams params) {
+            if (params.isAnchor()) {
+                RecordUserAction.record("MobileContextMenuLink");
+            } else if (params.isImage()) {
+                RecordUserAction.record("MobileContextMenuImage");
+            } else if (params.isSelectedText()) {
+                RecordUserAction.record("MobileContextMenuText");
+            } else if (params.isVideo()) {
+                RecordUserAction.record("MobileContextMenuVideo");
+            }
+
+            mDelegate.setParamsInfo(params.isImage(), params.isVideo());
+            super.buildContextMenu(menu, context, params);
+        }
+    }
+
+    @Override
+    protected ContextMenuPopulator createContextMenuPopulator() {
+        return new ChromeTabChromeContextMenuPopulator(
+                new ChromeTabChromeContextMenuItemDelegate());
+    }
+
+    /** @return The {@link BackgroundContentViewHelper} associated with the current tab. */
+    public BackgroundContentViewHelper getBackgroundContentViewHelper() {
+        return mBackgroundContentViewHelper;
+    }
+
+    @VisibleForTesting
+    public void setViewClientForTesting(ContentViewClient client) {
+        setContentViewClient(client);
+    }
+
+    @VisibleForTesting
+    public ContentViewClient getViewClientForTesting() {
+        return getContentViewClient();
+    }
+
+    private ContentViewClient createContentViewClient() {
+        return new TabContentViewClient() {
+            @Override
+            public void onBackgroundColorChanged(int color) {
+                ChromeTab.this.onBackgroundColorChanged(color);
+            }
+
+            @Override
+            public void onOffsetsForFullscreenChanged(
+                    float topControlsOffsetY, float contentOffsetY, float overdrawBottomHeight) {
+                onOffsetsChanged(topControlsOffsetY, contentOffsetY, overdrawBottomHeight,
+                        isShowingSadTab());
+            }
+
+            @Override
+            public void performWebSearch(String searchQuery) {
+                if (TextUtils.isEmpty(searchQuery)) return;
+                String url = TemplateUrlService.getInstance().getUrlForSearchQuery(searchQuery);
+                String headers = GeolocationHeader.getGeoHeader(getApplicationContext(), url,
+                        isIncognito());
+
+                LoadUrlParams loadUrlParams = new LoadUrlParams(url);
+                loadUrlParams.setVerbatimHeaders(headers);
+                loadUrlParams.setTransitionType(PageTransition.GENERATED);
+                mActivity.getTabModelSelector().openNewTab(loadUrlParams,
+                        TabLaunchType.FROM_LONGPRESS_FOREGROUND, ChromeTab.this, isIncognito());
+            }
+
+            @Override
+            public boolean doesPerformWebSearch() {
+                return true;
+            }
+
+            @Override
+            public SelectActionMode startActionMode(
+                    View view, ActionHandler actionHandler, boolean floating) {
+                if (floating) return null;
+                ChromeSelectActionModeCallback callback =
+                        new ChromeSelectActionModeCallback(view.getContext(), actionHandler);
+                ActionMode actionMode = view.startActionMode(callback);
+                return actionMode != null ? new SelectActionMode(actionMode) : null;
+            }
+
+            @Override
+            public boolean supportsFloatingActionMode() {
+                return false;
+            }
+
+            @Override
+            public ContentVideoViewClient getContentVideoViewClient() {
+                return new ActivityContentVideoViewClient(mActivity) {
+                    @Override
+                    public void enterFullscreenVideo(View view) {
+                        super.enterFullscreenVideo(view);
+                        FullscreenManager fullscreenManager = getFullscreenManager();
+                        if (fullscreenManager != null) {
+                            fullscreenManager.setOverlayVideoMode(true);
+                            // Disable double tap for video.
+                            if (getContentViewCore() != null) {
+                                getContentViewCore().updateDoubleTapSupport(false);
+                            }
+                        }
+                    }
+
+                    @Override
+                    public void exitFullscreenVideo() {
+                        FullscreenManager fullscreenManager = getFullscreenManager();
+                        if (fullscreenManager != null) {
+                            fullscreenManager.setOverlayVideoMode(false);
+                            // Disable double tap for video.
+                            if (getContentViewCore() != null) {
+                                getContentViewCore().updateDoubleTapSupport(true);
+                            }
+                        }
+                        super.exitFullscreenVideo();
+                    }
+                };
+            }
+        };
+    }
+
+    private WebContentsObserver createWebContentsObserver(WebContents webContents) {
+        return new WebContentsObserver(webContents) {
+            @Override
+            public void didFinishLoad(long frameId, String validatedUrl, boolean isMainFrame) {
+                PolicyAuditor auditor =
+                        ((ChromeMobileApplication) getApplicationContext()).getPolicyAuditor();
+                auditor.notifyAuditEvent(
+                        getApplicationContext(), AuditEvent.OPEN_URL_SUCCESS, validatedUrl, "");
+            }
+
+            @Override
+            public void didFailLoad(boolean isProvisionalLoad,
+                    boolean isMainFrame, int errorCode, String description, String failingUrl) {
+                PolicyAuditor auditor =
+                        ((ChromeMobileApplication) getApplicationContext()).getPolicyAuditor();
+                auditor.notifyAuditEvent(getApplicationContext(), AuditEvent.OPEN_URL_FAILURE,
+                        failingUrl, description);
+                if (errorCode == BLOCKED_BY_ADMINISTRATOR) {
+                    auditor.notifyAuditEvent(
+                            getApplicationContext(), AuditEvent.OPEN_URL_BLOCKED, failingUrl, "");
+                }
+            }
+
+            @Override
+            public void didCommitProvisionalLoadForFrame(
+                    long frameId, boolean isMainFrame, String url, int transitionType) {
+                if (!isMainFrame) return;
+
+                mIsNativePageCommitPending = false;
+                boolean isReload = (transitionType == PageTransition.RELOAD);
+                if (!maybeShowNativePage(url, isReload)) {
+                    showRenderedPage();
+                }
+
+                if (!mBackgroundContentViewHelper.hasPendingBackgroundPage()) {
+                    mHandler.removeMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD);
+                    mHandler.sendEmptyMessageDelayed(
+                            MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD, MAX_FULLSCREEN_LOAD_DELAY_MS);
+                    updateFullscreenEnabledState();
+                }
+
+                // http://crbug/426679 : if navigation is canceled due to intent handling, we want
+                // to go back to the last committed entry index which was saved before the
+                // navigation, and remove the empty entries from the navigation history.
+                if (mClearAllForwardHistoryRequired && getWebContents() != null) {
+                    NavigationController navigationController =
+                            getWebContents().getNavigationController();
+                    int lastCommittedEntryIndex = getLastCommittedEntryIndex();
+                    while (navigationController.canGoForward()) {
+                        boolean ret = navigationController.removeEntryAtIndex(
+                                lastCommittedEntryIndex + 1);
+                        assert ret;
+                    }
+                } else if (mShouldClearRedirectHistoryForTabClobbering
+                        && getWebContents() != null) {
+                    // http://crbug/479056: Even if we clobber the current tab, we want to remove
+                    // redirect history to be consistent.
+                    NavigationController navigationController =
+                            getWebContents().getNavigationController();
+                    int indexBeforeRedirection = mTabRedirectHandler
+                            .getLastCommittedEntryIndexBeforeStartingNavigation();
+                    int lastCommittedEntryIndex = getLastCommittedEntryIndex();
+                    for (int i = lastCommittedEntryIndex - 1; i > indexBeforeRedirection; --i) {
+                        boolean ret = navigationController.removeEntryAtIndex(i);
+                        assert ret;
+                    }
+                }
+                mClearAllForwardHistoryRequired = false;
+                mShouldClearRedirectHistoryForTabClobbering = false;
+            }
+
+            @Override
+            public void didAttachInterstitialPage() {
+                PolicyAuditor auditor =
+                        ((ChromeMobileApplication) getApplicationContext()).getPolicyAuditor();
+                auditor.notifyCertificateFailure(getWebContents(), getApplicationContext());
+            }
+
+            @Override
+            public void didDetachInterstitialPage() {
+                if (!maybeShowNativePage(getUrl(), false)) {
+                    showRenderedPage();
+                }
+            }
+
+            @Override
+            public void destroy() {
+                MediaNotificationService.updateMediaNotificationForTab(
+                        getApplicationContext(), getId(), false, false, false, getUrl());
+                super.destroy();
+            }
+        };
+    }
+
+    @Override
+    protected void didStartPageLoad(String validatedUrl, boolean showingErrorPage) {
+        if (mBackgroundContentViewHelper.isPageSwappingInProgress()) {
+            mLoadProgressAtViewSwapInTime = 0;
+        }
+
+        mIsFullscreenWaitingForLoad = !DomDistillerUrlUtils.isDistilledPage(validatedUrl);
+        mLoadProgressAtViewSwapInTime = 0;
+
+        super.didStartPageLoad(validatedUrl, showingErrorPage);
+    }
+
+    @Override
+    protected void didFinishPageLoad() {
+        // We should not mark finished if we have pending background page to swap in.
+        // We'll instead call didFinishPageLoad after the background page is swapped in.
+        if (mBackgroundContentViewHelper.hasPendingBackgroundPage()) return;
+
+        mLoadProgressAtViewSwapInTime = 0;
+
+        super.didFinishPageLoad();
+
+        // Handle the case where we were pre-renderered and the enable fullscreen message was
+        // never enqueued.
+        if (mIsFullscreenWaitingForLoad
+                && !mHandler.hasMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD)
+                && !mBackgroundContentViewHelper.hasPendingBackgroundPage()) {
+            mHandler.sendEmptyMessageDelayed(
+                    MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD, MAX_FULLSCREEN_LOAD_DELAY_MS);
+        }
+
+        maybeSetDataReductionProxyUsed();
+    }
+
+    @Override
+    protected void didFailPageLoad(int errorCode) {
+        mLoadProgressAtViewSwapInTime = 0;
+        cancelEnableFullscreenLoadDelay();
+        super.didFailPageLoad(errorCode);
+        updateFullscreenEnabledState();
+    }
+
+    private void cancelEnableFullscreenLoadDelay() {
+        mHandler.removeMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD);
+        mIsFullscreenWaitingForLoad = false;
+    }
+
+    /**
+     * Removes the enable fullscreen runnable from the UI queue and runs it immediately.
+     */
+    @VisibleForTesting
+    public void processEnableFullscreenRunnableForTest() {
+        if (mHandler.hasMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD)) {
+            mHandler.removeMessages(MSG_ID_ENABLE_FULLSCREEN_AFTER_LOAD);
+            enableFullscreenAfterLoad();
+        }
+    }
+
+    private void enableFullscreenAfterLoad() {
+        if (!mIsFullscreenWaitingForLoad) return;
+
+        mIsFullscreenWaitingForLoad = false;
+        updateFullscreenEnabledState();
+    }
+
+    @Override
+    protected boolean isHidingTopControlsEnabled() {
+        return super.isHidingTopControlsEnabled()  && !mIsFullscreenWaitingForLoad;
+    }
+
+    @Override
+    protected void handleTabCrash() {
+        super.handleTabCrash();
+
+        // Update the most recent minidump file with the logcat. Doing this asynchronously
+        // adds a race condition in the case of multiple simultaneously renderer crashses
+        // but because the data will be the same for all of them it is innocuous. We can
+        // attempt to do this regardless of whether it was a foreground tab in the event
+        // that it's a real crash and not just android killing the tab.
+        Context context = getApplicationContext();
+        Intent intent = MinidumpUploadService.createFindAndUploadLastCrashIntent(context);
+        context.startService(intent);
+        RecordUserAction.record("MobileBreakpadUploadAttempt");
+    }
+
+    @Override
+    protected void setContentViewCore(ContentViewCore cvc) {
+        try {
+            TraceEvent.begin("ChromeTab.setContentViewCore");
+            super.setContentViewCore(cvc);
+            mWebContentsObserver = createWebContentsObserver(cvc.getWebContents());
+
+            mDownloadDelegate = new ChromeDownloadDelegate(mActivity,
+                    mActivity.getTabModelSelector(), this);
+            cvc.setDownloadDelegate(mDownloadDelegate);
+            setInterceptNavigationDelegate(new InterceptNavigationDelegateImpl());
+
+            if (mGestureStateListener == null) mGestureStateListener = createGestureStateListener();
+            cvc.addGestureStateListener(mGestureStateListener);
+        } finally {
+            TraceEvent.end("ChromeTab.setContentViewCore");
+        }
+    }
+
+    private GestureStateListener createGestureStateListener() {
+        return new GestureStateListener() {
+            @Override
+            public void onFlingStartGesture(int vx, int vy, int scrollOffsetY, int scrollExtentY) {
+                onScrollingStateChanged();
+            }
+
+            @Override
+            public void onFlingEndGesture(int scrollOffsetY, int scrollExtentY) {
+                onScrollingStateChanged();
+            }
+
+            @Override
+            public void onScrollStarted(int scrollOffsetY, int scrollExtentY) {
+                onScrollingStateChanged();
+            }
+
+            @Override
+            public void onScrollEnded(int scrollOffsetY, int scrollExtentY) {
+                onScrollingStateChanged();
+            }
+
+            private void onScrollingStateChanged() {
+                FullscreenManager fullscreenManager = getFullscreenManager();
+                if (fullscreenManager == null) return;
+                fullscreenManager.onContentViewScrollingStateChanged(
+                        getContentViewCore() != null && getContentViewCore().isScrollInProgress());
+            }
+        };
+    }
+
+    @Override
+    protected void destroyContentViewCoreInternal(ContentViewCore cvc) {
+        super.destroyContentViewCoreInternal(cvc);
+
+        if (mGestureStateListener != null) {
+            cvc.removeGestureStateListener(mGestureStateListener);
+        }
+        if (mWebContentsObserver != null) {
+            mWebContentsObserver.destroy();
+        }
+        mWebContentsObserver = null;
+    }
+
+    @Override
+    public void stopLoading() {
+        super.stopLoading();
+        mBackgroundContentViewHelper.stopLoading();
+    }
+
+    @Override
+    public int getProgress() {
+        if (mBackgroundContentViewHelper.hasPendingBackgroundPage()
+                || mBackgroundContentViewHelper.isPageSwappingInProgress()) {
+            return mBackgroundContentViewHelper.getProgress();
+        }
+        int currentTabProgress = super.getProgress();
+        return Math.max(mLoadProgressAtViewSwapInTime, currentTabProgress);
+    }
+
+    /**
+     * @return Whether the tab is ready to display or it should be faded in as it loads.
+     */
+    public boolean shouldStall() {
+        return (isFrozen() || needsReload())
+                && !NativePageFactory.isNativePageUrl(getUrl(), isIncognito());
+    }
+
+    @Override
+    protected void showInternal(TabSelectionType type) {
+        super.showInternal(type);
+
+        // If the NativePage was frozen while in the background (see NativePageAssassin),
+        // recreate the NativePage now.
+        if (getNativePage() instanceof FrozenNativePage) {
+            maybeShowNativePage(getUrl(), true);
+        }
+        NativePageAssassin.getInstance().tabShown(this);
+    }
+
+    @Override
+    protected void restoreIfNeededInternal() {
+        super.restoreIfNeededInternal();
+    }
+
+    @Override
+    protected void hideInternal() {
+        super.hideInternal();
+        cancelEnableFullscreenLoadDelay();
+
+        // Allow this tab's NativePage to be frozen if it stays hidden for a while.
+        NativePageAssassin.getInstance().tabHidden(this);
+
+        mTabRedirectHandler.clear();
+    }
+
+    /**
+     * Checks if spdy proxy is enabled for input url.
+     * @param url Input url to check for spdy setting.
+     * @return true if url is enabled for spdy proxy.
+    */
+    protected boolean isSpdyProxyEnabledForUrl(String url) {
+        if (DataReductionProxySettings.getInstance().isDataReductionProxyEnabled()
+                && url != null && !url.toLowerCase(Locale.US).startsWith("https://")
+                && !isIncognito()) {
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void goBack() {
+        mBackgroundContentViewHelper.recordBack();
+        super.goBack();
+    }
+
+    @Override
+    public void reload() {
+        mBackgroundContentViewHelper.recordReload();
+        super.reload();
+    }
+
+    @Override
+    public void reloadIgnoringCache() {
+        mBackgroundContentViewHelper.recordReload();
+        super.reloadIgnoringCache();
+    }
+
+    @Override
+    public int loadUrl(LoadUrlParams params) {
+        try {
+            TraceEvent.begin("ChromeTab.loadUrl");
+
+            // The data reduction proxy can only be set to pass through mode via loading an image in
+            // a new tab. We squirrel away whether pass through mode was set, and check it in:
+            // @see ChromeWebContentsDelegateAndroid#onLoadStopped()
+            mLastPageLoadHasSpdyProxyPassthroughHeaders = false;
+            if (TextUtils.equals(params.getVerbatimHeaders(), PAGESPEED_PASSTHROUGH_HEADER)) {
+                mLastPageLoadHasSpdyProxyPassthroughHeaders = true;
+            }
+
+            // TODO(tedchoc): When showing the android NTP, delay the call to nativeLoadUrl until
+            //                the android view has entirely rendered.
+            if (!mIsNativePageCommitPending) {
+                mIsNativePageCommitPending = maybeShowNativePage(params.getUrl(), false);
+            }
+
+            return super.loadUrl(params);
+        } finally {
+            TraceEvent.end("ChromeTab.loadUrl");
+        }
+    }
+
+    @VisibleForTesting
+    public AuthenticatorNavigationInterceptor getAuthenticatorHelper() {
+        return getInterceptNavigationDelegate().mAuthenticatorHelper;
+    }
+
+    /**
+     * @return the TabRedirectHandler for the tab.
+     */
+    public TabRedirectHandler getTabRedirectHandler() {
+        return mTabRedirectHandler;
+    }
+
+    private class InterceptNavigationDelegateImpl implements InterceptNavigationDelegate {
+        final ExternalNavigationHandler mExternalNavHandler;
+        final AuthenticatorNavigationInterceptor mAuthenticatorHelper;
+
+        InterceptNavigationDelegateImpl() {
+            mExternalNavHandler = new ExternalNavigationHandler(mActivity);
+
+            mAuthenticatorHelper = ((ChromeMobileApplication) getApplicationContext())
+                    .createAuthenticatorNavigationInterceptor(ChromeTab.this);
+        }
+
+        public boolean shouldIgnoreNewTab(String url, boolean incognito) {
+            if (mAuthenticatorHelper != null && mAuthenticatorHelper.handleAuthenticatorUrl(url)) {
+                return true;
+            }
+
+            ExternalNavigationParams params = new ExternalNavigationParams.Builder(url, incognito)
+                    .setTab(ChromeTab.this)
+                    .setOpenInNewTab(true)
+                    .build();
+            return mExternalNavHandler.shouldOverrideUrlLoading(params)
+                    != ExternalNavigationHandler.OverrideUrlLoadingResult.NO_OVERRIDE;
+        }
+
+        @Override
+        public boolean shouldIgnoreNavigation(NavigationParams navigationParams) {
+            final String url = navigationParams.url;
+
+            if (mAuthenticatorHelper != null && mAuthenticatorHelper.handleAuthenticatorUrl(url)) {
+                return true;
+            }
+
+            mTabRedirectHandler.updateNewUrlLoading(navigationParams.pageTransitionType,
+                    navigationParams.isRedirect,
+                    navigationParams.hasUserGesture || navigationParams.hasUserGestureCarryover,
+                    mActivity.getLastUserInteractionTime(), getLastCommittedEntryIndex());
+            final boolean shouldCloseTab = shouldCloseContentsOnOverrideUrlLoadingAndLaunchIntent();
+            boolean isInitialTabLaunchInBackground =
+                    getLaunchType() == TabLaunchType.FROM_LONGPRESS_BACKGROUND && shouldCloseTab;
+            // http://crbug.com/448977: If a new tab is closed by this overriding, we should open an
+            // Intent in a new tab when Chrome receives it again.
+            ExternalNavigationParams params = new ExternalNavigationParams.Builder(
+                    url, isIncognito(), getReferrerUrl(), navigationParams.pageTransitionType,
+                    navigationParams.isRedirect)
+                    .setTab(ChromeTab.this)
+                    .setApplicationMustBeInForeground(true)
+                    .setRedirectHandler(mTabRedirectHandler)
+                    .setOpenInNewTab(shouldCloseTab)
+                    .setIsBackgroundTabNavigation(isHidden() && !isInitialTabLaunchInBackground)
+                    .setIsMainFrame(navigationParams.isMainFrame)
+                    .setNeedsToCloseTabAfterIncognitoDialog(shouldCloseTab
+                            && navigationParams.isMainFrame)
+                    .build();
+            ExternalNavigationHandler.OverrideUrlLoadingResult result =
+                    mExternalNavHandler.shouldOverrideUrlLoading(params);
+            mLastOverrideUrlLoadingResult = result;
+            switch (result) {
+                case OVERRIDE_WITH_EXTERNAL_INTENT:
+                    assert mExternalNavHandler.canExternalAppHandleUrl(url);
+                    if (navigationParams.isMainFrame) {
+                        onOverrideUrlLoadingAndLaunchIntent();
+                    }
+                    return true;
+                case OVERRIDE_WITH_CLOBBERING_TAB:
+                    mShouldClearRedirectHistoryForTabClobbering = true;
+                    return true;
+                case OVERRIDE_WITH_INCOGNITO_MODE:
+                    if (!shouldCloseTab && navigationParams.isMainFrame) {
+                        onOverrideUrlLoadingAndLaunchIntent();
+                    }
+                    return true;
+                case NO_OVERRIDE:
+                default:
+                    if (navigationParams.isExternalProtocol) {
+                        logBlockedNavigationToDevToolsConsole(url);
+                        return true;
+                    }
+                    return false;
+            }
+        }
+
+        private void logBlockedNavigationToDevToolsConsole(String url) {
+            int resId = mExternalNavHandler.canExternalAppHandleUrl(url)
+                    ? R.string.blocked_navigation_warning
+                    : R.string.unreachable_navigation_warning;
+            getWebContents().addMessageToDevToolsConsole(
+                    ConsoleMessageLevel.WARNING, getApplicationContext().getString(resId, url));
+        }
+
+        private String getReferrerUrl() {
+            // At this point, ContentView#getCurrentUrl() has already changed to
+            // be the URL to be loaded, so we need to check the last navigation entry
+            // instead. Note that for browser-initiated navigations, we rely on the
+            // mLastLoadUrlAddress check bailing early.
+            if (getWebContents() != null) {
+                return getWebContents().getNavigationController()
+                        .getOriginalUrlForVisibleNavigationEntry();
+            } else {
+                return null;
+            }
+        }
+    }
+
+    @Override
+    protected boolean shouldIgnoreNewTab(String url, boolean incognito) {
+        InterceptNavigationDelegateImpl delegate = getInterceptNavigationDelegate();
+        return delegate != null && delegate.shouldIgnoreNewTab(url, incognito);
+    }
+
+    private int getLastCommittedEntryIndex() {
+        if (getWebContents() == null) return -1;
+        return getWebContents().getNavigationController().getLastCommittedEntryIndex();
+    }
+
+    /**
+     * @return A potential fallback texture id to use when trying to draw this tab.
+     */
+    public int getFallbackTextureId() {
+        return INVALID_TAB_ID;
+    }
+
+    private boolean shouldCloseContentsOnOverrideUrlLoadingAndLaunchIntent() {
+        if (getWebContents() == null) return false;
+        if (!getWebContents().getNavigationController().canGoToOffset(0)) return true;
+
+        // http://crbug/415948 : if the last committed entry index which was saved before this
+        // navigation is invalid, it means that this navigation is the first one since this tab was
+        // created.
+        // In such case, we would like to close this tab.
+        if (mTabRedirectHandler.isOnNavigation()) {
+            return mTabRedirectHandler.getLastCommittedEntryIndexBeforeStartingNavigation()
+                    == TabRedirectHandler.INVALID_ENTRY_INDEX;
+        }
+        return false;
+    }
+
+    /**
+     * Called when Chrome decides to override URL loading and show an intent picker.
+     */
+    protected void onOverrideUrlLoadingAndLaunchIntent() {
+        if (getWebContents() == null) return;
+
+        // Before leaving Chrome, close the empty child tab.
+        // If a new tab is created through JavaScript open to load this
+        // url, we would like to close it as we will load this url in a
+        // different Activity.
+        if (shouldCloseContentsOnOverrideUrlLoadingAndLaunchIntent()) {
+            getChromeWebContentsDelegateAndroid().closeContents();
+        } else if (mTabRedirectHandler.isOnNavigation()) {
+            int lastCommittedEntryIndexBeforeNavigation =
+                    mTabRedirectHandler.getLastCommittedEntryIndexBeforeStartingNavigation();
+            if (getLastCommittedEntryIndex() > lastCommittedEntryIndexBeforeNavigation) {
+                // http://crbug/426679 : we want to go back to the last committed entry index which
+                // was saved before this navigation, and remove the empty entries from the
+                // navigation history.
+                mClearAllForwardHistoryRequired = true;
+                getWebContents().getNavigationController().goToNavigationIndex(
+                        lastCommittedEntryIndexBeforeNavigation);
+            }
+        }
+    }
+
+    @Override
+    protected InterceptNavigationDelegateImpl getInterceptNavigationDelegate() {
+        return (InterceptNavigationDelegateImpl) super.getInterceptNavigationDelegate();
+    }
+
+    @Override
+    public void setClosing(boolean closing) {
+        if (closing) mBackgroundContentViewHelper.recordTabClose();
+        super.setClosing(closing);
+    }
+
+    /**
+     * @return The reader mode manager for this tab that handles UI events for reader mode.
+     */
+    public ReaderModeManager getReaderModeManager() {
+        return mReaderModeManager;
+    }
+
+    public ReaderModeActivityDelegate getReaderModeActivityDelegate() {
+        if (!(mActivity instanceof CompositorChromeActivity)) return null;
+        return ((CompositorChromeActivity) mActivity).getReaderModeActivityDelegate();
+    }
+
+    /**
+     * Shows a native page for url if it's a valid chrome-native URL. Otherwise, does nothing.
+     * @param url The url of the current navigation.
+     * @param isReload Whether the current navigation is a reload.
+     * @return True, if a native page was displayed for url.
+     */
+    private boolean maybeShowNativePage(String url, boolean isReload) {
+        NativePage candidateForReuse = isReload ? null : getNativePage();
+        NativePage nativePage = NativePageFactory.createNativePageForURL(url, candidateForReuse,
+                this, mActivity.getTabModelSelector(), mActivity);
+        if (nativePage != null) {
+            showNativePage(nativePage);
+            notifyPageTitleChanged();
+            notifyFaviconChanged();
+            return true;
+        }
+        return false;
+    }
+
+    // TODO(dtrainor): Port more methods to the observer.
+    private final TabObserver mTabObserver = new EmptyTabObserver() {
+        @Override
+        public void onContentChanged(Tab tab) {
+            mLoadProgressAtViewSwapInTime = 0;
+        }
+
+        @Override
+        public void onSSLStateUpdated(Tab tab) {
+            PolicyAuditor auditor =
+                    ((ChromeMobileApplication) getApplicationContext()).getPolicyAuditor();
+            auditor.notifyCertificateFailure(getWebContents(), getApplicationContext());
+            updateFullscreenEnabledState();
+        }
+
+        @Override
+        public void onWebContentsSwapped(Tab tab, boolean didStartLoad, boolean didFinishLoad) {
+            if (!didStartLoad) return;
+
+            String url = tab.getUrl();
+            // Simulate the PAGE_LOAD_STARTED notification that we did not get.
+            didStartPageLoad(url, false);
+            if (didFinishLoad) {
+                // Simulate the PAGE_LOAD_FINISHED notification that we did not get.
+                didFinishPageLoad();
+            }
+        }
+    };
+
+    @VisibleForTesting
+    public OverrideUrlLoadingResult getLastOverrideUrlLoadingResultForTests() {
+        return mLastOverrideUrlLoadingResult;
+    }
+}