Avoid creating sync token when only change is new hardware video frame.

content/renderer/media/renderer_gpu_video_accelerator_factories.cc

 // Copyright 2013 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/renderer/media/renderer_gpu_video_accelerator_factories.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 
 #include "base/bind.h"
@@ skipping 179 matching lines @@
   DCHECK(task_runner_->BelongsToCurrentThread());
   if (CheckContextLost())
     return;
 
   cc::ContextProvider::ScopedContextLock lock(context_provider_);
   gpu::gles2::GLES2Interface* gles2 = lock.ContextGL();
   gles2->DeleteTextures(1, &texture_id);
   DCHECK_EQ(gles2->GetError(), static_cast<GLenum>(GL_NO_ERROR));
 }
 
+gpu::SyncToken RendererGpuVideoAcceleratorFactories::CreateSyncToken() {
+  cc::ContextProvider::ScopedContextLock lock(context_provider_);
+  gpu::gles2::GLES2Interface* gl = lock.ContextGL();
+  gpu::SyncToken sync_token;
+  const GLuint64 fence_sync = gl->InsertFenceSyncCHROMIUM();
+  gl->ShallowFlushCHROMIUM();
+  gl->GenSyncTokenCHROMIUM(fence_sync, sync_token.GetData());
+  return sync_token;
+}
+
 void RendererGpuVideoAcceleratorFactories::WaitSyncToken(
     const gpu::SyncToken& sync_token) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   if (CheckContextLost())
     return;
 
   cc::ContextProvider::ScopedContextLock lock(context_provider_);
   gpu::gles2::GLES2Interface* gles2 = lock.ContextGL();
   gles2->WaitSyncTokenCHROMIUM(sync_token.GetConstData());
 
@@ skipping 96 matching lines @@
   context_provider_refptr_ = nullptr;
 }
 
 scoped_refptr<ContextProviderCommandBuffer>
 RendererGpuVideoAcceleratorFactories::ContextProviderMainThread() {
   DCHECK(main_thread_task_runner_->BelongsToCurrentThread());
   return context_provider_refptr_;
 }
 
 }  // namespace content