Implement vrdisplayactivate for GVR DON.

chrome/browser/android/vr_shell/vr_shell_delegate.h

Index: chrome/browser/android/vr_shell/vr_shell_delegate.h
diff --git a/chrome/browser/android/vr_shell/vr_shell_delegate.h b/chrome/browser/android/vr_shell/vr_shell_delegate.h
index 91b8082873742eb32b5c9c739a7c31a9e50e92c0..6a83f2e061ba7e77a4aa36f8b8ea543cb2c091f7 100644
--- a/chrome/browser/android/vr_shell/vr_shell_delegate.h
+++ b/chrome/browser/android/vr_shell/vr_shell_delegate.h
@@ -29,11 +29,12 @@ class VrShellDelegate : public device::GvrDelegateProvider {
   base::WeakPtr<device::GvrDeviceProvider> GetDeviceProvider();
 
   void SetPresentResult(JNIEnv* env, jobject obj, jboolean result);
+  void DisplayActivate(JNIEnv* env, jobject obj);
 
   // device::GvrDelegateProvider implementation
-  void RequestWebVRPresent(
-      base::WeakPtr<device::GvrDeviceProvider> device_provider,
-      const base::Callback<void(bool)>& callback) override;
+  void SetDeviceProvider(
+      base::WeakPtr<device::GvrDeviceProvider> device_provider) override;
+  void RequestWebVRPresent(const base::Callback<void(bool)>& callback) override;
   void ExitWebVRPresent() override;
   base::WeakPtr<device::GvrDelegate> GetNonPresentingDelegate() override;
   void DestroyNonPresentingDelegate() override;