TabBase: Add ContentView/NativePage ownership

chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java

Index: chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
new file mode 100644
index 0000000000000000000000000000000000000000..a14953849851e485828fd4114a1269750899a8e5
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/TabObserver.java
@@ -0,0 +1,37 @@
+// Copyright (c) 2013 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;
+
+/**
+ * An observer that is notified of changes to a {@link TabBase} object.
+ */
+public interface TabObserver {
+
+    /**
+     * Called when the load progress of a {@link TabBase} changes.
+     * @param tab      The notifying {@link TabBase}.
+     * @param progress The new progress from [0,100].
+     */
+    public void onLoadProgressChanged(TabBase tab, int progress);
+
+    /**
+     * Called when the URL of a {@link TabBase} changes.
+     * @param tab The notifying {@link TabBase}.
+     * @param url The new URL.
+     */
+    public void onUpdateUrl(TabBase tab, String url);
+
+    /**
+     * Called when a {@link TabBase} is being destroyed.
+     * @param tab The notifying {@link TabBase}.
+     */
+    public void onDestroyed(TabBase tab);
+
+    /**
+     * Called when the tab content changes (to/from native pages or swapping native WebContents).
+     * @param tab The notifying {@link TabBase}.
+     */
+    public void onContentChanged(TabBase tab);
+}