Ensure VR UI does not miss controller button clicks

chrome/browser/android/vr_shell/vr_shell_gl.h

 // Copyright 2016 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 CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 
 #include <memory>
 #include <queue>
 #include <utility>
@@ skipping 114 matching lines @@
   std::vector<const ContentRectangle*> GetElementsInDrawOrder(
       const gvr::Mat4f& view_matrix,
       const std::vector<const ContentRectangle*>& elements);
   void DrawCursor(const gvr::Mat4f& render_matrix);
   bool ShouldDrawWebVr();
   void DrawWebVr();
   bool WebVrPoseByteIsValid(int pose_index_byte);
 
   void UpdateController();
   void HandleControllerInput(const gvr::Vec3f& forward_vector);
+  void HandleControllerAppButtonActivity(
+      const gvr::Vec3f& controller_direction);
   void SendEventsToTarget(InputTarget input_target, int pixel_x, int pixel_y);
   void SendGesture(InputTarget input_target,
                    std::unique_ptr<blink::WebInputEvent> event);
   void CreateUiSurface();
   void OnUIFrameAvailable();
   void OnContentFrameAvailable();
   void OnWebVRFrameAvailable();
   bool GetPixelEncodedFrameIndex(uint16_t* frame_index);
 
   void OnVSync();
@@ skipping 91 matching lines @@
   gvr::Vec3f controller_start_direction_;
 
   base::WeakPtrFactory<VrShellGl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellGl);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_