Adds locks for CommandBufferProxyImpl invalidation

media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc

Index: media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc
diff --git a/media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc b/media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc
index 94d53179e207707debf6a7cd2b11cbc96dab5ddd..cf5a85045f2f736b39abdd354105e462235946fa 100644
--- a/media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc
+++ b/media/gpu/ipc/client/gpu_video_decode_accelerator_host.cc
@@ -12,6 +12,7 @@
 #include "gpu/ipc/client/gpu_channel_host.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
+#include "media/base/bind_to_current_loop.h"
 #include "media/gpu/ipc/common/media_messages.h"
 
 namespace media {
@@ -26,6 +27,9 @@ GpuVideoDecodeAcceleratorHost::GpuVideoDecodeAcceleratorHost(
   DCHECK(channel_);
   DCHECK(impl_);
   impl_->AddDeletionObserver(this);
+  channel_error_cb_ = media::BindToCurrentLoop(

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

Just store a task runner and bind/post to it from OnWillDeleteImpl? That would
be a lot easier to follow/less indirection to what is going on.

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

Done.

+      base::Bind(&GpuVideoDecodeAcceleratorHost::OnChannelError,
+                 weak_this_factory_.GetWeakPtr()));
 }
 
 GpuVideoDecodeAcceleratorHost::~GpuVideoDecodeAcceleratorHost() {
@@ -33,6 +37,8 @@ GpuVideoDecodeAcceleratorHost::~GpuVideoDecodeAcceleratorHost() {
 
   if (channel_ && decoder_route_id_ != MSG_ROUTING_NONE)
     channel_->RemoveRoute(decoder_route_id_);
+
+  base::AutoLock lock(impl_lock_);
   if (impl_)
     impl_->RemoveDeletionObserver(this);
 }
@@ -79,6 +85,7 @@ bool GpuVideoDecodeAcceleratorHost::Initialize(const Config& config,
   DCHECK(CalledOnValidThread());
   client_ = client;
 
+  base::AutoLock lock(impl_lock_);
   if (!impl_)
     return false;
 
@@ -180,11 +187,11 @@ void GpuVideoDecodeAcceleratorHost::Destroy() {
 }
 
 void GpuVideoDecodeAcceleratorHost::OnWillDeleteImpl() {
-  DCHECK(CalledOnValidThread());
+  base::AutoLock lock(impl_lock_);
   impl_ = NULL;
 
   // The gpu::CommandBufferProxyImpl is going away; error out this VDA.
-  OnChannelError();
+  channel_error_cb_.Run();
 }
 
 void GpuVideoDecodeAcceleratorHost::PostNotifyError(Error error) {