Ensure that the open gl context is current in the DXVA decoder while processing configuration chang…

content/common/gpu/media/dxva_video_decode_accelerator_win.cc

Index: content/common/gpu/media/dxva_video_decode_accelerator_win.cc
diff --git a/content/common/gpu/media/dxva_video_decode_accelerator_win.cc b/content/common/gpu/media/dxva_video_decode_accelerator_win.cc
index c15d7db9971a69226dc80ced3b608f63d4c5475c..ac82e28ab68c438e01dbdf63e041d1151c6387c6 100644
--- a/content/common/gpu/media/dxva_video_decode_accelerator_win.cc
+++ b/content/common/gpu/media/dxva_video_decode_accelerator_win.cc
@@ -2832,6 +2832,9 @@ HRESULT DXVAVideoDecodeAccelerator::CheckConfigChanged(
 void DXVAVideoDecodeAccelerator::ConfigChanged(
     const Config& config) {
   DCHECK(main_thread_task_runner_->BelongsToCurrentThread());
+  RETURN_AND_NOTIFY_ON_FAILURE(make_context_current_.Run(),

[sandersd (OOO until July 31), 2016/04/04 23:35:46]

Should it be Invalidate() and/or Initialize() that do this?

[ananta, 2016/04/05 00:00:36]

In the general case Invalidate and Initialize get called in the context of the
IPC handler which makes the context current. I added a call to make the context
current in Invalidate as a best effort as it gets called during errors. We don't
need to do this in Initialize. 

For this case DismissStaleBuffers needs the context to be current. Making it
current in the top level call seems like the right way to go.

+    "Failed to make context current", PLATFORM_FAILURE, );
+
   SetState(kConfigChange);
   DismissStaleBuffers(true);

[jbauman, 2016/04/05 00:02:18]

DismissStaleBuffers is called from other places (e.g. directly as a callback),
so we should probably make it current there.

Also, we should probably do this for DeferredDismissStaleBuffer as well. 

[ananta, 2016/04/05 00:22:10]

Done.

   Invalidate();