Pause drawing webvr when the App button is pressed

chrome/browser/android/vr_shell/vr_shell_gl.cc

 // 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.
 
 #include "chrome/browser/android/vr_shell/vr_shell_gl.h"
 
 #include <chrono>
 #include <limits>
 #include <utility>
 
@@ skipping 642 matching lines @@
                     &gesture_xz_angle)) {
       if (fabs(gesture_xz_angle) > kMinAppButtonGestureAngleRad) {
         direction =
             gesture_xz_angle < 0 ? UiInterface::LEFT : UiInterface::RIGHT;
         main_thread_task_runner_->PostTask(
             FROM_HERE, base::Bind(&VrShell::AppButtonGesturePerformed,
                                   weak_vr_shell_, direction));
       }
     }
     if (direction == UiInterface::NONE) {
+      content_paused_ = !content_paused_;

[bshe, 2017/04/21 21:08:42]

perhaps rename to content_rendering_enabled_ to make it more readable?

[ymalik, 2017/04/28 00:12:04]

Done.

+      scene_->SetWebVrRenderingEnabled(!content_paused_);
       main_thread_task_runner_->PostTask(
-          FROM_HERE, base::Bind(&VrShell::AppButtonPressed, weak_vr_shell_));
+          FROM_HERE, base::Bind(&VrShell::AppButtonPressed, weak_vr_shell_,
+                                content_paused_));
     }
   }
 }
 
 void VrShellGl::SendEventsToTarget(InputTarget input_target,
                                    int pixel_x,
                                    int pixel_y) {
   std::vector<std::unique_ptr<WebGestureEvent>> gesture_list =
       controller_->DetectGestures();
   double timestamp = gesture_list.front()->TimeStampSeconds();
@@ skipping 650 matching lines @@
   // InitializeGl. Revisit if the initialization order changes.
   device::mojom::VRDisplayInfoPtr info =
       device::GvrDelegate::CreateVRDisplayInfo(gvr_api_.get(),
                                                webvr_surface_size_, device_id);
   main_thread_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&RunVRDisplayInfoCallback, callback, base::Passed(&info)));
 }
 
 }  // namespace vr_shell