TabBase: Add ContentView/NativePage ownership

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

Index: chrome/android/java/src/org/chromium/chrome/browser/EmptyTabObserver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/EmptyTabObserver.java b/chrome/android/java/src/org/chromium/chrome/browser/EmptyTabObserver.java
new file mode 100644
index 0000000000000000000000000000000000000000..8b5898e6a8dfa6669a8147d73a329d4596ded0a7
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/EmptyTabObserver.java
@@ -0,0 +1,23 @@
+// 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 implementation of the {@link TabObserver} which has empty implementations of all methods.
+ */
+public class EmptyTabObserver implements TabObserver {
+
+    @Override
+    public void onLoadProgressChanged(TabBase tab, int progress) { }
+
+    @Override
+    public void onUpdateUrl(TabBase tab, String url) { }
+
+    @Override
+    public void onDestroyed(TabBase tab) { }
+
+    @Override
+    public void onContentChanged(TabBase tab) { }
+}