Change V8VarConverter::FromV8Value to complete synchronously if possible

content/renderer/pepper/message_channel.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/message_channel.h"
 
 #include <cstdlib>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 276 matching lines @@
   plugin_message_queue_.push_back(VarConversionResult());
   if (variant->type == NPVariantType_Object) {
     // Convert NPVariantType_Object in to an appropriate PP_Var like Dictionary,
     // Array, etc. Note NPVariantToVar would convert to an "Object" PP_Var,
     // which we don't support for Messaging.
 
     // Calling WebBindings::toV8Value creates a wrapper around NPVariant so it
     // won't result in a deep copy.
     v8::Handle<v8::Value> v8_value = WebBindings::toV8Value(variant);
     V8VarConverter v8_var_converter(instance_->pp_instance());
-    v8_var_converter.FromV8Value(
-        v8_value,
-        v8::Isolate::GetCurrent()->GetCurrentContext(),
-        base::Bind(&MessageChannel::FromV8ValueComplete,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   &plugin_message_queue_.back()));
+    V8VarConverter::VarResult conversion_result =
+        v8_var_converter.FromV8Value(
+            v8_value,
+            v8::Isolate::GetCurrent()->GetCurrentContext(),
+            base::Bind(&MessageChannel::FromV8ValueComplete,
+                       weak_ptr_factory_.GetWeakPtr(),
+                       &plugin_message_queue_.back()));
+    if (conversion_result.completed_synchronously) {
+      plugin_message_queue_.back().ConversionCompleted(
+          conversion_result.var,
+          conversion_result.success);
+    }
   } else {
     plugin_message_queue_.back().ConversionCompleted(
         ScopedPPVar(ScopedPPVar::PassRef(),
                     NPVariantToPPVar(instance(), variant)),
         true);
     DCHECK(plugin_message_queue_.back().var().get().type != PP_VARTYPE_OBJECT);
   }
 }
 
 void MessageChannel::PostMessageToJavaScript(PP_Var message_data) {
@@ skipping 160 matching lines @@
     return true;
   }
   return false;
 }
 
 void MessageChannel::SetReadOnlyProperty(PP_Var key, PP_Var value) {
   internal_properties_[PPVarToNPIdentifier(key)] = ScopedPPVar(value);
 }
 
 }  // namespace content