Upstream TabAndroid abstract class.

chrome/browser/android/tab_android.cc

Index: chrome/browser/android/tab_android.cc
diff --git a/ui/aura/display_observer.cc b/chrome/browser/android/tab_android.cc
similarity index 59%
copy from ui/aura/display_observer.cc
copy to chrome/browser/android/tab_android.cc
index d9120fdebf2fd503337241ef90c5dd361dac95d8..1b9345a82a6140472c37d9694a3b5281c0df8573 100644
--- a/ui/aura/display_observer.cc
+++ b/chrome/browser/android/tab_android.cc
@@ -2,11 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ui/aura/display_observer.h"
+#include "chrome/browser/android/tab_android.h"
 
-namespace aura {
-
-DisplayObserver::~DisplayObserver() {
+TabAndroid::TabAndroid() : tab_id_(-1) {
 }
 
-}  // namespace aura
+TabAndroid::~TabAndroid() {
+}