Add Mojo API for Blink hit testing

content/renderer/input/frame_input_handler_impl.h

 // Copyright 2017 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.
 
 #ifndef CONTENT_RENDERER_INPUT_FRAME_INPUT_HANDLER_IMPL_H_
 #define CONTENT_RENDERER_INPUT_FRAME_INPUT_HANDLER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "content/common/input/input_handler.mojom.h"
 #include "content/renderer/render_frame_impl.h"
@@ skipping 70 matching lines @@
 
    private:
     RenderFrameImpl* render_frame_;
     bool original_select_range_value_;
     bool original_pasting_value_;
   };
 
   FrameInputHandlerImpl(base::WeakPtr<RenderFrameImpl> render_frame,
                         mojom::FrameInputHandlerRequest request);
 
-  void RunOnMainThread(const base::Closure& closure);
+  void RunOnMainThread(base::OnceClosure closure);
   void BindNow(mojom::FrameInputHandlerRequest request);
   void ExecuteCommandOnMainThread(const std::string& command,
                                   UpdateState state);
+
   void Release();
 
   mojo::Binding<mojom::FrameInputHandler> binding_;
 
   // |render_frame_| should only be accessed on the main thread. Use
   // GetRenderFrame so that it will DCHECK this for you.
   base::WeakPtr<RenderFrameImpl> render_frame_;
 
   scoped_refptr<MainThreadEventQueue> input_event_queue_;
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
 
   base::WeakPtr<FrameInputHandlerImpl> weak_this_;
   base::WeakPtrFactory<FrameInputHandlerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameInputHandlerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_INPUT_FRAME_INPUT_HANDLER_IMPL_H_