Flash: Don't lose a reference to the Graphics3D from the VideoDecoder.

ppapi/shared_impl/ppb_video_decoder_shared.cc

 // Copyright (c) 2012 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 "ppapi/shared_impl/ppb_video_decoder_shared.h"
 
 #include "base/logging.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/shared_impl/ppb_graphics_3d_shared.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 #include "ppapi/thunk/enter.h"
 
 namespace ppapi {
 
 PPB_VideoDecoder_Shared::PPB_VideoDecoder_Shared(PP_Instance instance)
     : Resource(OBJECT_IS_IMPL, instance),
       graphics_context_(0),
       gles2_impl_(NULL) {
 }
 
 PPB_VideoDecoder_Shared::PPB_VideoDecoder_Shared(
     const HostResource& host_resource)
     : Resource(OBJECT_IS_PROXY, host_resource),
       graphics_context_(0),
       gles2_impl_(NULL) {
 }
 
 PPB_VideoDecoder_Shared::~PPB_VideoDecoder_Shared() {
+  // Destroy() must be called before the object is destroyed.
+  DCHECK(graphics_context_ == 0);
 }
 
 thunk::PPB_VideoDecoder_API* PPB_VideoDecoder_Shared::AsPPB_VideoDecoder_API() {
   return this;
 }
 
 void PPB_VideoDecoder_Shared::InitCommon(
     PP_Resource graphics_context,
     gpu::gles2::GLES2Implementation* gles2_impl) {
   DCHECK(graphics_context);
   DCHECK(!gles2_impl_ && !graphics_context_);
   gles2_impl_ = gles2_impl;
   PpapiGlobals::Get()->GetResourceTracker()->AddRefResource(graphics_context);
   graphics_context_ = graphics_context;
 }
 
 void PPB_VideoDecoder_Shared::Destroy() {
-  graphics_context_ = 0;
+  if (graphics_context_) {
+    PpapiGlobals::Get()->GetResourceTracker()->ReleaseResource(
+        graphics_context_);
+    graphics_context_ = 0;
+  }
   gles2_impl_ = NULL;
-  PpapiGlobals::Get()->GetResourceTracker()->ReleaseResource(graphics_context_);
 }
 
 bool PPB_VideoDecoder_Shared::SetFlushCallback(
     scoped_refptr<TrackedCallback> callback) {
   if (TrackedCallback::IsPending(flush_callback_))
     return false;
   flush_callback_ = callback;
   return true;
 }
 
@@ skipping 37 matching lines @@
         graphics_context_, false);
     DCHECK(enter_g3d.succeeded());
     PPB_Graphics3D_Shared* graphics3d =
         static_cast<PPB_Graphics3D_Shared*>(enter_g3d.object());
     PPB_Graphics3D_Shared::ScopedNoLocking dont_lock(graphics3d);
     gles2_impl_->Flush();
   }
 }
 
 }  // namespace ppapi