Make sure gin Handles exist before using them

content/shell/renderer/test_runner/gamepad_controller.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/gamepad_controller.h"
 
 #include "content/shell/renderer/test_runner/TestInterfaces.h"
 #include "content/shell/renderer/test_runner/WebTestDelegate.h"
 #include "gin/arguments.h"
 #include "gin/handle.h"
@@ skipping 50 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<GamepadControllerBindings> bindings =
       gin::CreateHandle(isolate, new GamepadControllerBindings(controller));
+  if (bindings.IsEmpty())
+    return;
   v8::Handle<v8::Object> global = context->Global();
   global->Set(gin::StringToV8(isolate, "gamepadController"), bindings.ToV8());
 }
 
 GamepadControllerBindings::GamepadControllerBindings(
     base::WeakPtr<GamepadController> controller)
     : controller_(controller) {}
 
 GamepadControllerBindings::~GamepadControllerBindings() {}
 
@@ skipping 154 matching lines @@
   if (index < 0 || index >= static_cast<int>(WebGamepads::itemsLengthCap))
     return;
   if (axis < 0 || axis >= static_cast<int>(WebGamepad::axesLengthCap))
     return;
   gamepads_.items[index].axes[axis] = data;
   if (delegate_)
     delegate_->setGamepadData(gamepads_);
 }
 
 }  // namespace content