Use the correct v8 context for conversions when calling into the plugin from JS

content/renderer/pepper/pepper_plugin_instance_impl.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_plugin_instance_impl.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 654 matching lines @@
 
 v8::Local<v8::Object> PepperPluginInstanceImpl::GetMessageChannelObject() {
   return v8::Local<v8::Object>::New(isolate_, message_channel_object_);
 }
 
 void PepperPluginInstanceImpl::MessageChannelDestroyed() {
   message_channel_ = NULL;
   message_channel_object_.Reset();
 }
 
 v8::Local<v8::Context> PepperPluginInstanceImpl::GetContext() {

[dmichael (off chromium), 2014/09/23 16:16:54]

Maybe we should rename this to "GetMainWorldContext" and comment that it should
only be used when that's the correct context, or the context doesn't matter
(like when dispatching a MessageEvent, since the event will get re-constituted
in the listeners' respective contexts anyway).

[raymes, 2014/09/24 00:19:45]

Done.

-  if (!container_ ||
-      container_->element().isNull() ||
-      container_->element().document().isNull() ||
-      !container_->element().document().frame()) {
+  if (!container_)
     return v8::Handle<v8::Context>();
-  }
+
+  if (container_->element().isNull())
+    return v8::Handle<v8::Context>();
+
+  if (container_->element().document().isNull())
+    return v8::Handle<v8::Context>();
+
+  if (!container_->element().document().frame())
+    return v8::Handle<v8::Context>();
 
   v8::Local<v8::Context> context =
       container_->element().document().frame()->mainWorldScriptContext();
   DCHECK(context->GetIsolate() == isolate_);
   return context;
 }
 
 void PepperPluginInstanceImpl::Delete() {
   is_deleted_ = true;
 
@@ skipping 2685 matching lines @@
     // Running out-of-process. Initiate an IPC call to notify the plugin
     // process.
     ppapi::proxy::HostDispatcher* dispatcher =
         ppapi::proxy::HostDispatcher::GetForInstance(pp_instance());
     dispatcher->Send(new PpapiMsg_PPPInstance_HandleDocumentLoad(
         ppapi::API_ID_PPP_INSTANCE, pp_instance(), pending_host_id, data));
   }
 }
 
 }  // namespace content