Mac: Ensure that Mach messages always get a reply

content/browser/browser_io_surface_manager_mac.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_BROWSER_IO_SURFACE_MANAGER_MAC_H_
 #define CONTENT_BROWSER_BROWSER_IO_SURFACE_MANAGER_MAC_H_
 
 #include <mach/mach.h>
 
 #include <map>
@@ skipping 61 matching lines @@
   ~BrowserIOSurfaceManager() override;
 
   // Performs any initialization work.
   bool Initialize();
 
   // Message handler that is invoked on |dispatch_source_| when an
   // incoming message needs to be received.
   void HandleRequest();
 
   // Message handlers that are invoked from HandleRequest.
-  bool HandleRegisterIOSurfaceRequest(
+  void HandleRegisterIOSurfaceRequest(
       const IOSurfaceManagerHostMsg_RegisterIOSurface& request,
       IOSurfaceManagerMsg_RegisterIOSurfaceReply* reply);
   bool HandleUnregisterIOSurfaceRequest(
       const IOSurfaceManagerHostMsg_UnregisterIOSurface& request);
-  bool HandleAcquireIOSurfaceRequest(
+  void HandleAcquireIOSurfaceRequest(
       const IOSurfaceManagerHostMsg_AcquireIOSurface& request,
       IOSurfaceManagerMsg_AcquireIOSurfaceReply* reply);
 
   // Whether or not the class has been initialized.
   bool initialized_;
 
   // The Mach port on which the server listens.
   base::mac::ScopedMachReceiveRight server_port_;
 
   // The dispatch source and queue on which Mach messages will be received.
@@ skipping 18 matching lines @@
   // Mutex that guards |initialized_|, |io_surfaces_|, |child_process_ids_|
   // and |gpu_process_token_|.
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserIOSurfaceManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_IO_SURFACE_MANAGER_MAC_H_