Make sure gin Handles exist before using them

content/shell/renderer/test_runner/event_sender.cc

 // Copyright 2014 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/shell/renderer/test_runner/event_sender.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "content/shell/renderer/test_runner/MockSpellCheck.h"
@@ skipping 418 matching lines @@
   v8::Isolate* isolate = blink::mainThreadIsolate();
   v8::HandleScope handle_scope(isolate);
   v8::Handle<v8::Context> context = frame->mainWorldScriptContext();
   if (context.IsEmpty())
     return;
 
   v8::Context::Scope context_scope(context);
 
   gin::Handle<EventSenderBindings> bindings =
       gin::CreateHandle(isolate, new EventSenderBindings(sender));
+  if (bindings.IsEmpty())
+    return;
   v8::Handle<v8::Object> global = context->Global();
   global->Set(gin::StringToV8(isolate, "eventSender"), bindings.ToV8());
 }
 
 gin::ObjectTemplateBuilder
 EventSenderBindings::GetObjectTemplateBuilder(v8::Isolate* isolate) {
   return gin::Wrappable<EventSenderBindings>::GetObjectTemplateBuilder(isolate)
       .SetMethod("enableDOMUIEventLogging",
                  &EventSenderBindings::EnableDOMUIEventLogging)
       .SetMethod("fireKeyboardEventsToElement",
@@ skipping 1698 matching lines @@
       }
       default:
         NOTREACHED();
     }
   }
 
   replaying_saved_events_ = false;
 }
 
 }  // namespace content