Post GpuMemoryBufferVideoFramePool deletion on media thread

media/video/gpu_memory_buffer_video_frame_pool.cc

 // Copyright 2015 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 "media/video/gpu_memory_buffer_video_frame_pool.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 739 matching lines @@
   auto it = std::find(resources_pool_.begin(), resources_pool_.end(),
                       frame_resources);
   DCHECK(it != resources_pool_.end());
   // We want the pool to behave in a FIFO way.
   // This minimizes the chances of locking the buffer that might be
   // still needed for drawing.
   std::swap(*it, resources_pool_.back());
   frame_resources->SetIsInUse(false);
 }
 
-GpuMemoryBufferVideoFramePool::GpuMemoryBufferVideoFramePool() {}
+GpuMemoryBufferVideoFramePool::GpuMemoryBufferVideoFramePool()
+    : weak_ptr_factory_(this) {}
 
 GpuMemoryBufferVideoFramePool::GpuMemoryBufferVideoFramePool(
     const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
     const scoped_refptr<base::TaskRunner>& worker_task_runner,
     GpuVideoAcceleratorFactories* gpu_factories)
     : pool_impl_(
-          new PoolImpl(media_task_runner, worker_task_runner, gpu_factories)) {
+          new PoolImpl(media_task_runner, worker_task_runner, gpu_factories)),
+      weak_ptr_factory_(this) {
   base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
       pool_impl_.get(), "GpuMemoryBufferVideoFramePool", media_task_runner);
 }
 
 GpuMemoryBufferVideoFramePool::~GpuMemoryBufferVideoFramePool() {
   base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
       pool_impl_.get());
 }
 
 void GpuMemoryBufferVideoFramePool::MaybeCreateHardwareFrame(
     const scoped_refptr<VideoFrame>& video_frame,
     const FrameReadyCB& frame_ready_cb) {
   DCHECK(video_frame);
   pool_impl_->CreateHardwareFrame(video_frame, frame_ready_cb);
 }
 
+base::WeakPtr<GpuMemoryBufferVideoFramePool>
+GpuMemoryBufferVideoFramePool::GetWeakPtr() {
+  return weak_ptr_factory_.GetWeakPtr();
+}
+
 }  // namespace media