Implement features in NativeViewHostAura for scroll end effect

ui/views/controls/native/native_view_host_wrapper.h

Index: ui/views/controls/native/native_view_host_wrapper.h
diff --git a/ui/views/controls/native/native_view_host_wrapper.h b/ui/views/controls/native/native_view_host_wrapper.h
index 3b3cb37fbdc0b5382b8819ca7223a0b4f88b28fd..de6aa5d512d8021a3dc6d38c0b36c9003697ee83 100644
--- a/ui/views/controls/native/native_view_host_wrapper.h
+++ b/ui/views/controls/native/native_view_host_wrapper.h
@@ -24,6 +24,11 @@ class VIEWS_EXPORT NativeViewHostWrapper {
   // initialization.
   virtual void NativeViewWillAttach() = 0;
 
+  // Called at the end of attaching a gfx::NativeView to the associated
+  // NativeViewHost, allowing the wrapper to perform platform-specific
+  // operations that need to occur after the gfx::NativeView is attached.
+  virtual void NativeViewAttached() = 0;
+
   // Called before the attached gfx::NativeView is detached from the
   // NativeViewHost, allowing the wrapper to perform platform-specific
   // cleanup. |destroyed| is true if the native view is detached