Adding a WindowAndroidHelper class.

chrome/browser/android/tab_android.cc

Index: chrome/browser/android/tab_android.cc
diff --git a/chrome/browser/android/tab_android.cc b/chrome/browser/android/tab_android.cc
index ba3ddbbfb193a5605a66ff2cb8a6652c64b9a064..f0009750429e9df599d4d5d07af3cf9feb205538 100644
--- a/chrome/browser/android/tab_android.cc
+++ b/chrome/browser/android/tab_android.cc
@@ -3,16 +3,23 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/android/tab_android.h"
+#include "chrome/browser/ui/android/window_android_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "content/public/browser/web_contents.h"
 
-
 TabContents* TabAndroid::GetOrCreateTabContents(
     content::WebContents* web_contents) {
   TabContents* tab_contents = TabContents::FromWebContents(web_contents);
-  return tab_contents ? tab_contents : TabContents::Factory::CreateTabContents(
-      web_contents);
+  if (!tab_contents) {
+    tab_contents = TabContents::Factory::CreateTabContents(web_contents);
+    InitTabHelpers(web_contents);
+  }
+  return tab_contents;
+}
+
+void TabAndroid::InitTabHelpers(content::WebContents* web_contents) {
+  WindowAndroidHelper::CreateForWebContents(web_contents);
 }
 
 TabContents* TabAndroid::InitTabContentsFromView(JNIEnv* env,