Virtual context MakeCurrent tweaks.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 2fad0053b50fcf7c655d36c7efde44a5f0034b62..554607d0715033f4b39906f46dcf184280d4a80c 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -3195,6 +3195,9 @@ void GLES2DecoderImpl::Destroy(bool have_context) {
     group_ = NULL;
   }
 
+  // Keep the context current, since the surface destructor might clean up
+  // resources.
+  surface_ = NULL;

[epenner, 2013/05/28 23:36:56]

This looks good but see have_context above. It looks like we don't handle
!have_context (although I don't know the details of when that occurs or how the
other objects get cleaned up in that case).

Perhaps we could do decoder_->SetSurface(NULL) back in the other code location
where we know we have the context?

It would really help if we could do surface->Destroy(), but it's probably
reference-counting faux pas to determine if we have the last reference.

   if (context_.get()) {
     context_->ReleaseCurrent(NULL);
     context_ = NULL;