Handle extension webrequest API on the IO thread. This speeds up blocking event

chrome/browser/extensions/extension_event_router.h

Index: chrome/browser/extensions/extension_event_router.h
diff --git a/chrome/browser/extensions/extension_event_router.h b/chrome/browser/extensions/extension_event_router.h
index 4ebae0c50e3a386ab345ac93ebbfe67c3f6cc83d..2e5597ba119e3e09507f54ee1260f9bf150dae98 100644
--- a/chrome/browser/extensions/extension_event_router.h
+++ b/chrome/browser/extensions/extension_event_router.h
@@ -13,6 +13,7 @@
 #include "base/memory/ref_counted.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
+#include "ipc/ipc_message.h"
 
 class GURL;
 class Extension;
@@ -22,11 +23,13 @@ class RenderProcessHost;
 
 class ExtensionEventRouter : public NotificationObserver {
  public:
-  // Returns true if the given extension can see events and data from another
-  // sub-profile (incognito to original profile, or vice versa).
-  static bool CanCrossIncognito(Profile* profile,
-                                const std::string& extension_id);
-  static bool CanCrossIncognito(Profile* profile, const Extension* extension);
+  // Sends an event via ipc_sender to the given extension. Can be called on
+  // any thread.
+  static void DispatchEvent(IPC::Message::Sender* ipc_sender,
+                            const std::string& extension_id,
+                            const std::string& event_name,
+                            const std::string& event_args,
+                            const GURL& event_url);
 
   explicit ExtensionEventRouter(Profile* profile);
   virtual ~ExtensionEventRouter();