Add Mojo API for Blink hit testing

content/renderer/input/frame_input_hit_test_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_HIT_TEST_IMPL_H_
+#define CONTENT_RENDERER_INPUT_FRAME_INPUT_HIT_TEST_IMPL_H_
+
+#include "base/memory/ref_counted.h"
+#include "content/renderer/render_frame_impl.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "services/viz/public/interfaces/hit_test/input_hit_test.mojom.h"
+
+namespace content {
+class MainThreadEventQueue;
+
+// This class provides an implementation of FrameInputHitTest mojo interface.
+class FrameInputHitTestImpl : public viz::mojom::FrameInputHitTest {
+ public:
+  static void CreateMojoService(base::WeakPtr<RenderFrameImpl> render_frame,
+                                viz::mojom::FrameInputHitTestRequest request);
+
+  void HitTestFrameAt(const gfx::Point& point,
+                      HitTestFrameAtCallback callback) override;
+
+ private:
+  ~FrameInputHitTestImpl() override;
+
+  FrameInputHitTestImpl(base::WeakPtr<RenderFrameImpl> render_frame,
+                        viz::mojom::FrameInputHitTestRequest request);
+
+  void RunOnMainThread(base::OnceClosure closure);
+  void HitTestOnMainThread(const gfx::Point&, HitTestFrameAtCallback);
+
+  void BindNow(viz::mojom::FrameInputHitTestRequest request);
+  void Release();
+
+  mojo::Binding<viz::mojom::FrameInputHitTest> 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<FrameInputHitTestImpl> weak_this_;
+  base::WeakPtrFactory<FrameInputHitTestImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(FrameInputHitTestImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_INPUT_FRAME_INPUT_HIT_TEST_IMPL_H_