Use gpu::Mailbox instead of std:string in IPCs

gpu/command_buffer/service/mailbox_manager.h

Index: gpu/command_buffer/service/mailbox_manager.h
diff --git a/gpu/command_buffer/service/mailbox_manager.h b/gpu/command_buffer/service/mailbox_manager.h
index e06ef2dcb74efb4862dde4c685179eebd4fe87cf..01b74b2b1473c652f3078e92800bbbc20e0bec3a 100644
--- a/gpu/command_buffer/service/mailbox_manager.h
+++ b/gpu/command_buffer/service/mailbox_manager.h
@@ -64,11 +64,11 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
   // iterator in the MailboxToTextureMap to be able to manage changes to
   // the TextureToMailboxMap efficiently.
   typedef std::multimap<Texture*, TargetName> TextureToMailboxMap;
-  typedef std::map<
-      TargetName,
-      TextureToMailboxMap::iterator,
-      std::pointer_to_binary_function<
-          const TargetName&, const TargetName&, bool> > MailboxToTextureMap;
+  typedef std::map<TargetName,
+                   TextureToMailboxMap::iterator,
+                   std::pointer_to_binary_function<const TargetName&,
+                                                   const TargetName&,
+                                                   bool> > MailboxToTextureMap;
 
   MailboxToTextureMap mailbox_to_textures_;
   TextureToMailboxMap textures_to_mailboxes_;
@@ -80,4 +80,3 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_H_
 
-