ozone: gpu: Add plumbing for platform-specific gpu messaging

content/browser/gpu/gpu_process_host.h

 // Copyright (c) 2012 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_GPU_GPU_PROCESS_HOST_H_
 #define CONTENT_BROWSER_GPU_GPU_PROCESS_HOST_H_
 
 #include <map>
 #include <queue>
 #include <set>
 #include <string>
 
+#include "base/atomic_sequence_num.h"
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/time.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/common/content_export.h"
 #include "content/common/gpu/gpu_memory_uma_stats.h"
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/public/browser/browser_child_process_host_delegate.h"
@@ skipping 121 matching lines @@
   GpuProcessKind kind();
 
   void ForceShutdown();
 
   void BeginFrameSubscription(
       int surface_id,
       base::WeakPtr<RenderWidgetHostViewFrameSubscriber> subscriber);
   void EndFrameSubscription(int surface_id);
   void LoadedShader(const std::string& key, const std::string& data);
 
+  int32 GenerateRouteID();

[rjkroege, 2014/06/16 21:38:49]

does this need to be public? I missed seeing it being called anywhere outside of
gpu_process_host.cc

+
  private:
   static bool ValidateHost(GpuProcessHost* host);
 
   GpuProcessHost(int host_id, GpuProcessKind kind);
   virtual ~GpuProcessHost();
 
   bool Init();
 
   // Post an IPC message to the UI shim's message handler on the UI thread.
   void RouteOnUIThread(const IPC::Message& message);
@@ skipping 108 matching lines @@
 
   std::string shader_prefix_key_;
 
   // Keep an extra reference to the SurfaceRef stored in the GpuSurfaceTracker
   // in this map so that we don't destroy it whilst the GPU process is
   // drawing to it.
   typedef std::multimap<int, scoped_refptr<GpuSurfaceTracker::SurfaceRef> >
       SurfaceRefMap;
   SurfaceRefMap surface_refs_;
 
+  base::AtomicSequenceNumber next_route_id_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuProcessHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_GPU_GPU_PROCESS_HOST_H_