Only unbind a Graphics2D on destruction when we're actually bound.

content/renderer/pepper/pepper_graphics_2d_host.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 "content/renderer/pepper/pepper_graphics_2d_host.h"
 
 #include "content/public/renderer/renderer_ppapi_host.h"
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/host/dispatch_host_message.h"
 #include "ppapi/host/host_message_context.h"
@@ skipping 24 matching lines @@
 
 PepperGraphics2DHost::PepperGraphics2DHost(RendererPpapiHost* host,
                                            PP_Instance instance,
                                            PP_Resource resource)
     : ResourceHost(host->GetPpapiHost(), instance, resource),
       graphics_2d_(new webkit::ppapi::PPB_Graphics2D_Impl(instance)),
       is_running_in_process_(host->IsRunningInProcess()) {
 }
 
 PepperGraphics2DHost::~PepperGraphics2DHost() {
-  // Unbind from the instance when destoryed.
-  PP_Instance instance = graphics_2d_->pp_instance();
-  ppapi::thunk::EnterInstanceNoLock enter(instance);
-  if (enter.succeeded())
-    enter.functions()->BindGraphics(instance, 0);
+  // Unbind from the instance when destroyed if we're still bound.
+  webkit::ppapi::PluginInstance* bound_instance =
+      graphics_2d_->bound_instance();
+  if (bound_instance)
+    bound_instance->BindGraphics(bound_instance->pp_instance(), 0);
 }
 
 int32_t PepperGraphics2DHost::OnResourceMessageReceived(
     const IPC::Message& msg,
     ppapi::host::HostMessageContext* context) {
   IPC_BEGIN_MESSAGE_MAP(PepperGraphics2DHost, msg)
 #if !defined(OS_NACL)
     PPAPI_DISPATCH_HOST_RESOURCE_CALL(
         PpapiHostMsg_Graphics2D_PaintImageData,
         OnHostMsgPaintImageData)
@@ skipping 144 matching lines @@
                                                 int32_t pp_error) {
   if (!data || pp_error != PP_OK)
     return;
   PepperGraphics2DHost* self = (PepperGraphics2DHost*) data;
   self->host()->SendReply(self->flush_reply_context_,
                           PpapiPluginMsg_Graphics2D_FlushAck());
 }
 #endif  // !defined(OS_NACL)
 
 }  // namespace content