Infrastructure for temportarily relinquishing GPU resources.

content/common/gpu/gpu_channel_manager.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/common/gpu/gpu_channel_manager.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "content/common/gpu/gpu_channel.h"
 #include "content/common/gpu/gpu_memory_buffer_factory.h"
@@ skipping 85 matching lines @@
           gpu_memory_buffer_factory_.get())),
       weak_factory_(this) {
   DCHECK(router_);
   DCHECK(io_message_loop);
   DCHECK(shutdown_event);
   channel_->AddFilter(filter_.get());
 }
 
 GpuChannelManager::~GpuChannelManager() {
   gpu_channels_.clear();
-  if (default_offscreen_surface_.get()) {
-    default_offscreen_surface_->Destroy();
-    default_offscreen_surface_ = NULL;
-  }
+  OnDeleteDefaultOffscreenSurface();

[jbauman, 2014/11/12 01:47:28]

This shouldn't be necessary, as it'll be deleted automatically.

[GusFernandez, 2014/11/15 02:11:56]

See below.

 }
 
 gpu::gles2::ProgramCache* GpuChannelManager::program_cache() {
   if (!program_cache_.get() &&
       (gfx::g_driver_gl.ext.b_GL_ARB_get_program_binary ||
        gfx::g_driver_gl.ext.b_GL_OES_get_program_binary) &&
       !CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableGpuProgramCache)) {
     program_cache_.reset(new gpu::gles2::MemoryProgramCache());
   }
@@ skipping 35 matching lines @@
 
 bool GpuChannelManager::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(GpuChannelManager, msg)
     IPC_MESSAGE_HANDLER(GpuMsg_EstablishChannel, OnEstablishChannel)
     IPC_MESSAGE_HANDLER(GpuMsg_CloseChannel, OnCloseChannel)
     IPC_MESSAGE_HANDLER(GpuMsg_CreateViewCommandBuffer,
                         OnCreateViewCommandBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_DestroyGpuMemoryBuffer, OnDestroyGpuMemoryBuffer)
     IPC_MESSAGE_HANDLER(GpuMsg_LoadedShader, OnLoadedShader)
+    IPC_MESSAGE_HANDLER(GpuMsg_DeleteDefaultOffscreenSurface,
+                        OnDeleteDefaultOffscreenSurface)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 bool GpuChannelManager::Send(IPC::Message* msg) { return router_->Send(msg); }
 
 void GpuChannelManager::OnEstablishChannel(int client_id,
                                            bool share_context,
                                            bool allow_future_sync_points) {
@@ skipping 141 matching lines @@
 }
 
 gfx::GLSurface* GpuChannelManager::GetDefaultOffscreenSurface() {
   if (!default_offscreen_surface_.get()) {
     default_offscreen_surface_ =
         gfx::GLSurface::CreateOffscreenGLSurface(gfx::Size());
   }
   return default_offscreen_surface_.get();
 }
 
+void GpuChannelManager::OnDeleteDefaultOffscreenSurface() {
+    if (default_offscreen_surface_.get()) {
+      default_offscreen_surface_->Destroy();

[jbauman, 2014/11/12 01:47:28]

This Destroy should be unnecessary, as it'll be called in the destructor.

[GusFernandez, 2014/11/15 02:11:56]

The whole point is to release the default_offscreen_surface temporarily without
having to tear down the whole GPU channel.

+      default_offscreen_surface_ = NULL;
+  }
+}
+
 }  // namespace content