Removing unnecessary creation of RenderViewHostDestructionObserver for all WebContents

extensions/browser/process_manager.h

Index: extensions/browser/process_manager.h
diff --git a/extensions/browser/process_manager.h b/extensions/browser/process_manager.h
index f283c799e1ce9949777ac206617cdd7fd0123b08..1059db3028bfcfbf17c09886e04b823eeb1b2a8e 100644
--- a/extensions/browser/process_manager.h
+++ b/extensions/browser/process_manager.h
@@ -190,7 +190,9 @@ class ProcessManager : public content::NotificationObserver {
 
   // Potentially registers a RenderViewHost, if it is associated with an
   // extension. Does nothing if this is not an extension renderer.
-  void RegisterRenderViewHost(content::RenderViewHost* render_view_host);
+  // Returns true, if render_view_host was registered (it is associated
+  // with an extension).
+  bool RegisterRenderViewHost(content::RenderViewHost* render_view_host);
 
   // Unregister RenderViewHosts and clear background page data for an extension
   // which has been unloaded.