Adds locks for CommandBufferProxyImpl invalidation

media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc

Index: media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc
diff --git a/media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc b/media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc
index 5a1f3994e21597282489467867bcd0939bab73dc..4590723702a6509d10903abeadc468114dad7112 100644
--- a/media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc
+++ b/media/gpu/ipc/client/gpu_video_encode_accelerator_host.cc
@@ -8,6 +8,7 @@
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "gpu/ipc/client/gpu_channel_host.h"
+#include "media/base/bind_to_current_loop.h"
 #include "media/base/video_frame.h"
 #include "media/gpu/gpu_video_accelerator_util.h"
 #include "media/gpu/ipc/common/media_messages.h"
@@ -26,12 +27,17 @@ GpuVideoEncodeAcceleratorHost::GpuVideoEncodeAcceleratorHost(
   DCHECK(channel_);
   DCHECK(impl_);
   impl_->AddDeletionObserver(this);
+  channel_error_cb_ = media::BindToCurrentLoop(

[danakj, 2017/01/13 18:27:50]

same

[emircan, 2017/01/13 19:08:14]

Done.

+      base::Bind(&GpuVideoEncodeAcceleratorHost::OnChannelError,
+                 weak_this_factory_.GetWeakPtr()));
 }
 
 GpuVideoEncodeAcceleratorHost::~GpuVideoEncodeAcceleratorHost() {
   DCHECK(CalledOnValidThread());
   if (channel_ && encoder_route_id_ != MSG_ROUTING_NONE)
     channel_->RemoveRoute(encoder_route_id_);
+
+  base::AutoLock lock(impl_lock_);
   if (impl_)
     impl_->RemoveDeletionObserver(this);
 }
@@ -83,6 +89,8 @@ bool GpuVideoEncodeAcceleratorHost::Initialize(
     Client* client) {
   DCHECK(CalledOnValidThread());
   client_ = client;
+
+  base::AutoLock lock(impl_lock_);
   if (!impl_) {
     DLOG(ERROR) << "impl_ destroyed";
     return false;
@@ -174,11 +182,11 @@ void GpuVideoEncodeAcceleratorHost::Destroy() {
 }
 
 void GpuVideoEncodeAcceleratorHost::OnWillDeleteImpl() {
-  DCHECK(CalledOnValidThread());
+  base::AutoLock lock(impl_lock_);
   impl_ = nullptr;
 
   // The gpu::CommandBufferProxyImpl is going away; error out this VEA.
-  OnChannelError();
+  channel_error_cb_.Run();
 }
 
 void GpuVideoEncodeAcceleratorHost::EncodeSharedMemoryFrame(