Notify VRDeviceProviders when there are pages listening for vrdisplayactivate

chrome/browser/android/vr_shell/vr_shell_delegate.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_DELEGATE_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_DELEGATE_H_
 
 #include <jni.h>
 
 #include "base/android/jni_weak_ref.h"
@@ skipping 20 matching lines @@
   // Called by the Java VrShellDelegate. Returns true if the GvrDeviceProvider
   // needs to handle shutdown first.
   void ExitWebVRIfNecessary(JNIEnv* env, jobject obj);
 
   // device::GvrDelegateProvider implementation
   bool RequestWebVRPresent(
       base::WeakPtr<device::GvrDeviceProvider> device_provider) override;
   void ExitWebVRPresent() override;
   base::WeakPtr<device::GvrDelegate> GetNonPresentingDelegate() override;
   void DestroyNonPresentingDelegate() override;
+  void SetListeningForActivate(bool listening) override;
 
  private:
   std::unique_ptr<device::GvrDelegate> non_presenting_delegate_;
   base::android::ScopedJavaGlobalRef<jobject> j_vr_shell_delegate_;
   base::WeakPtr<device::GvrDeviceProvider> device_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellDelegate);
 };
 
 bool RegisterVrShellDelegate(JNIEnv* env);
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_DELEGATE_H_