Pause drawing webvr when the App button is pressed

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 198 matching lines @@
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::CancelableClosure vsync_task_;
   base::TimeTicks vsync_timebase_;
   base::TimeDelta vsync_interval_;
 
   base::TimeDelta pending_time_;
   bool pending_vsync_ = false;
   GetVSyncCallback callback_;
   bool received_frame_ = false;
+  bool content_paused_ = false;
   mojo::Binding<device::mojom::VRVSyncProvider> binding_;
   device::mojom::VRSubmitFrameClientPtr submit_client_;
 
   base::WeakPtr<VrShell> weak_vr_shell_;
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
 
   UiScene* scene_ = nullptr;
 
   uint8_t frame_index_ = 0;
   // Larger than frame_index_ so it can be initialized out-of-band.
   uint16_t last_frame_index_ = -1;
 
   // Attributes for gesture detection while holding app button.
   gfx::Vector3dF controller_start_direction_;
 
   std::unique_ptr<FPSMeter> fps_meter_;
 
   base::WeakPtrFactory<VrShellGl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellGl);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_