3D Compositing in <browser>, first draft.

content/browser/gpu/gpu_process_host.cc

 // 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.
 
 #include "content/browser/gpu/gpu_process_host.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 503 matching lines @@
     const gfx::GLSurfaceHandle& compositing_surface,
     int surface_id,
     int client_id,
     const GPUCreateCommandBufferConfig& init_params,
     const CreateCommandBufferCallback& callback) {
   TRACE_EVENT0("gpu", "GpuProcessHostUIShim::CreateViewCommandBuffer");
 
   DCHECK(CalledOnValidThread());
 
 #if defined(TOOLKIT_GTK)
-  // There should only be one such command buffer (for the compositor).  In
-  // practice, if the GPU process lost a context, GraphicsContext3D with
-  // associated command buffer and view surface will not be gone until new
-  // one is in place and all layers are reattached.
   linked_ptr<SurfaceRef> surface_ref;
-  SurfaceRefMap::iterator it = surface_refs_.find(surface_id);
-  if (it != surface_refs_.end())
-    surface_ref = (*it).second;
-  else
-    surface_ref.reset(new SurfaceRef(compositing_surface.handle));
+  if (compositing_surface.handle) {
+    // There should only be one such command buffer (for the compositor).  In
+    // practice, if the GPU process lost a context, GraphicsContext3D with
+    // associated command buffer and view surface will not be gone until new
+    // one is in place and all layers are reattached.
+    SurfaceRefMap::iterator it = surface_refs_.find(surface_id);
+    if (it != surface_refs_.end())
+      surface_ref = (*it).second;
+    else
+      surface_ref.reset(new SurfaceRef(compositing_surface.handle));
+  }
 #endif  // defined(TOOLKIT_GTK)
 
   if (!compositing_surface.is_null() &&
       Send(new GpuMsg_CreateViewCommandBuffer(
           compositing_surface, surface_id, client_id, init_params))) {
     create_command_buffer_requests_.push(callback);
 #if defined(TOOLKIT_GTK)
-    surface_refs_.insert(std::make_pair(surface_id, surface_ref));
+    if (compositing_surface.handle)
+      surface_refs_.insert(std::make_pair(surface_id, surface_ref));
 #endif
   } else {
     CreateCommandBufferError(callback, MSG_ROUTING_NONE);
   }
 }
 
 void GpuProcessHost::OnChannelEstablished(
     const IPC::ChannelHandle& channel_handle) {
   TRACE_EVENT0("gpu", "GpuProcessHostUIShim::OnChannelEstablished");
 
@@ skipping 315 matching lines @@
     const IPC::ChannelHandle& channel_handle,
     base::ProcessHandle renderer_process_for_gpu,
     const content::GPUInfo& gpu_info) {
   callback.Run(channel_handle, gpu_info);
 }
 
 void GpuProcessHost::CreateCommandBufferError(
     const CreateCommandBufferCallback& callback, int32 route_id) {
   callback.Run(route_id);
 }