Rework FlushSync to return early if commands have been processed since the last update

gpu/demos/framework/window.cc

 // Copyright (c) 2011 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 "gpu/demos/framework/window.h"
 
 #include "base/callback.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/client/gles2_lib.h"
 #include "gpu/command_buffer/service/command_buffer_service.h"
@@ skipping 51 matching lines @@
   GpuScheduler* gpu_scheduler(
       new GpuScheduler(command_buffer.get(), NULL));
   if (!gpu_scheduler->Initialize(hwnd, gfx::Size(),
                                  gpu::gles2::DisallowedExtensions(),
                                  NULL, std::vector<int32>(),
                                  NULL, 0)) {
     return false;
   }
 
   command_buffer->SetPutOffsetChangeCallback(
-      NewCallback(gpu_scheduler, &GpuScheduler::ProcessCommands));
+      NewCallback(gpu_scheduler, &GpuScheduler::PutChanged));
 
   GLES2CmdHelper* helper = new GLES2CmdHelper(command_buffer.get());
   if (!helper->Initialize(kCommandBufferSize)) {
     // TODO(alokp): cleanup.
     return false;
   }
 
   int32 transfer_buffer_id =
       command_buffer->CreateTransferBuffer(kTransferBufferSize, -1);
   Buffer transfer_buffer =
       command_buffer->GetTransferBuffer(transfer_buffer_id);
   if (transfer_buffer.ptr == NULL) return false;
 
   ::gles2::Initialize();
   ::gles2::SetGLContext(new GLES2Implementation(helper,
                                                 transfer_buffer.size,
                                                 transfer_buffer.ptr,
                                                 transfer_buffer_id,
                                                 false));
   return command_buffer.release() != NULL;
 }
 
 }  // namespace demos
 }  // namespace gpu