Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/toolbar/ToolbarTabController.java

+// 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.toolbar;
+
+/**
+ * Handles toolbar triggered actions on the specific tab.
+ */
+public interface ToolbarTabController {
+    /**
+     * If the page is currently loading, this will trigger the tab to stop.  If the page is fully
+     * loaded, this will trigger a refresh.
+     *
+     * <p>The buttons of the toolbar will be updated as a result of making this call.
+     */
+    void stopOrReloadCurrentTab();
+
+    /**
+     * Navigates the current Tab back.
+     * @return Whether or not the current Tab did go back.
+     */
+    boolean back();
+
+    /**
+     * Navigates the current Tab forward.
+     * @return Whether or not the current Tab did go forward.
+     */
+    boolean forward();
+
+    /**
+     * Opens hompage in the current tab.
+     */
+    void openHomepage();
+}