[Android] Upstream remaining changes to NTP UI code.

chrome/common/chrome_notification_types.h

Index: chrome/common/chrome_notification_types.h
diff --git a/chrome/common/chrome_notification_types.h b/chrome/common/chrome_notification_types.h
index efba24f3fd59c74ba8b23aa5b8bf294607e96044..b438f4c8abedc6b263bc0c4ba5c7b05434daa8c1 100644
--- a/chrome/common/chrome_notification_types.h
+++ b/chrome/common/chrome_notification_types.h
@@ -151,6 +151,17 @@ enum NotificationType {
   // starting and finishing all painting.
   NOTIFICATION_INITIAL_NEW_TAB_UI_LOAD,
 
+#if defined(OS_ANDROID)
+  // Indicates that the new tab page is ready.  This is different than
+  // NOTIFICATION_INITIAL_NEW_TAB_UI_LOAD as the NTP might do some more in-page
+  // navigations after it's done loading, potentially causing flakyness in tests
+  // that would navigate as soon as the NTP is done loading.
+  // When this notification happen, it guarantees the page is not going to do
+  // any further navigation.
+  // The source is the TabContents containing the NTP.
+  NOTIFICATION_NEW_TAB_READY,
+#endif
+
   // Used to fire notifications about how long various events took to
   // complete.  E.g., this is used to get more fine grained timings from the
   // new tab page.  The source is a WebContents and the details is a