[Android] Stop hiding the RWHV layer subtree when hiding the widget

ui/android/window_android.h

Index: ui/android/window_android.h
diff --git a/ui/android/window_android.h b/ui/android/window_android.h
index cb201cd9e45b0e48a3de8782b9f7fad930973e4c..73e7686c61b56cd02d3329fe9aa9f2778215a82e 100644
--- a/ui/android/window_android.h
+++ b/ui/android/window_android.h
@@ -43,6 +43,7 @@ class UI_ANDROID_EXPORT WindowAndroid {
 
   // Compositor callback relay.
   void OnCompositingDidCommit();
+  void OnVisibilityChanged(bool visible);
 
   void AttachCompositor(WindowAndroidCompositor* compositor);
   void DetachCompositor();
@@ -59,6 +60,8 @@ class UI_ANDROID_EXPORT WindowAndroid {
                jlong time_micros,
                jlong period_micros);
   void Animate(base::TimeTicks begin_frame_time);
+  void OnActivityPaused(JNIEnv* env, jobject obj);
+  void OnActivityResumed(JNIEnv* env, jobject obj);
 
  private:
   ~WindowAndroid();