Revert 186627

content/browser/browser_plugin/browser_plugin_guest_manager.h

Index: content/browser/browser_plugin/browser_plugin_guest_manager.h
===================================================================
--- content/browser/browser_plugin/browser_plugin_guest_manager.h	(revision 186756)
+++ content/browser/browser_plugin/browser_plugin_guest_manager.h	(working copy)
@@ -22,10 +22,6 @@
 class Point;
 }
 
-namespace gpu {
-struct Mailbox;
-}
-
 namespace IPC {
 class Message;
 }  // namespace IPC
@@ -96,7 +92,7 @@
   void OnUnhandledSwapBuffersACK(int instance_id,
                                  int route_id,
                                  int gpu_host_id,
-                                 const gpu::Mailbox& mailbox_name,
+                                 const std::string& mailbox_name,
                                  uint32 sync_point);
 
   // Static factory instance (always NULL outside of tests).