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..7a27e73a1a5262cf7e77c35eee8a4e6683369cda 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -54,7 +54,6 @@ enum UiAction {
   HISTORY_BACK = 0,
   HISTORY_FORWARD,
   RELOAD,
-  SET_CONTENT_PAUSED,
   SHOW_TAB,
   OPEN_NEW_TAB,
   EXIT_PRESENT,
@@ -108,6 +107,7 @@ class VrShell : public device::PresentingGvrDelegate,
                     const base::android::JavaParamRef<jobject>& obj,
                     jboolean incognito,
                     jint id);
+  void OnContentPaused(bool paused);
   base::android::ScopedJavaGlobalRef<jobject> TakeContentSurface(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj);
@@ -127,7 +127,6 @@ class VrShell : public device::PresentingGvrDelegate,
   void ContentSurfaceChanged(jobject surface);
   void GvrDelegateReady();
   void AppButtonGesturePerformed(UiInterface::Direction direction);
-  void AppButtonPressed();
 
   void ContentPhysicalBoundsChanged(
       JNIEnv* env,
@@ -156,7 +155,6 @@ class VrShell : public device::PresentingGvrDelegate,
  private:
   ~VrShell() override;
   void PostToGlThreadWhenReady(const base::Closure& task);
-  void SetContentPaused(bool paused);
   void SetUiState();
 
   // device::GvrDelegate implementation.