Implement features in NativeViewHostAura for scroll end effect

ui/views/controls/webview/webview.h

Index: ui/views/controls/webview/webview.h
diff --git a/ui/views/controls/webview/webview.h b/ui/views/controls/webview/webview.h
index 7e50914131c28fd7a3cef8d1c4cfe609eac9b3fd..f1e10f6f5195cdace495c92febde995d543b8d4e 100644
--- a/ui/views/controls/webview/webview.h
+++ b/ui/views/controls/webview/webview.h
@@ -12,6 +12,7 @@
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "ui/views/accessibility/native_view_accessibility.h"
+#include "ui/views/controls/native/native_view_host.h"
 #include "ui/views/controls/webview/webview_export.h"
 #include "ui/views/view.h"
 
@@ -21,8 +22,6 @@ class SiteInstance;
 
 namespace views {
 
-class NativeViewHost;
-
 class WEBVIEW_EXPORT WebView : public View,
                                public content::NotificationObserver,
                                public content::WebContentsDelegate,
@@ -71,6 +70,11 @@ class WEBVIEW_EXPORT WebView : public View,
   //         resizing performance during interactive resizes and animations.
   void SetFastResize(bool fast_resize);
 
+  // Controls how the clip is positioned relative to the contents when using
+  // fast resize. Details of the meaning of the parameter can be found in
+  // native_view_host.h
+  void SetFastResizeGravity(NativeViewHost::Gravity gravity);
+
   // Called when the WebContents is focused.
   // TODO(beng): This view should become a WebContentsViewObserver when a
   //             WebContents is attached, and not rely on the delegate to