Remove NOTIFICATION_RENDER_VIEW_HOST_CHANGED.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 2e6a5f7556dd8378d2b796a9d676fa9c9ce0472c..0e108157dc9865221681bdb7ac0e681d8a3dbfe6 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -3345,14 +3345,6 @@ void WebContentsImpl::NotifyViewSwapped(RenderViewHost* old_host,
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     RenderViewHostChanged(old_host, new_host));
 
-  // TODO(avi): Remove. http://crbug.com/170921
-  std::pair<RenderViewHost*, RenderViewHost*> details =
-      std::make_pair(old_host, new_host);
-  NotificationService::current()->Notify(
-      NOTIFICATION_RENDER_VIEW_HOST_CHANGED,
-      Source<WebContents>(this),
-      Details<std::pair<RenderViewHost*, RenderViewHost*> >(&details));
-
   // Ensure that the associated embedder gets cleared after a RenderViewHost
   // gets swapped, so we don't reuse the same embedder next time a
   // RenderViewHost is attached to this WebContents.