Pause drawing webvr when the App button is pressed

chrome/browser/android/vr_shell/vr_shell.h

Index: chrome/browser/android/vr_shell/vr_shell.h
diff --git a/chrome/browser/android/vr_shell/vr_shell.h b/chrome/browser/android/vr_shell/vr_shell.h
index 20572ccda6663f2427176b5138158358514b22e6..2bfd5fc91c16612f812c026b65a5544ada86e1b4 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -127,7 +127,7 @@ class VrShell : public device::PresentingGvrDelegate,
   void ContentSurfaceChanged(jobject surface);
   void GvrDelegateReady();
   void AppButtonGesturePerformed(UiInterface::Direction direction);
-  void AppButtonPressed();
+  void AppButtonPressed(bool content_paused);
 
   void ContentPhysicalBoundsChanged(
       JNIEnv* env,
@@ -156,7 +156,7 @@ class VrShell : public device::PresentingGvrDelegate,
  private:
   ~VrShell() override;
   void PostToGlThreadWhenReady(const base::Closure& task);
-  void SetContentPaused(bool paused);
+  void OnContentPaused(bool paused);
   void SetUiState();
 
   // device::GvrDelegate implementation.