android webview: Keep zoom methods synchronous

android_webview/browser/browser_view_renderer.h

 // Copyright (c) 2013 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 ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_
 #define ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 64 matching lines @@
 
   void SetOffscreenPreRaster(bool enabled);
 
   // View update notifications.
   void SetIsPaused(bool paused);
   void SetViewVisibility(bool visible);
   void SetWindowVisibility(bool visible);
   void OnSizeChanged(int width, int height);
   void OnAttachedToWindow(int width, int height);
   void OnDetachedFromWindow();
+  void SynchronizeRendererScroll();
   void OnComputeScroll(base::TimeTicks animation_time);
 
   // Sets the scale for logical<->physical pixel conversions.
   void SetDipScale(float dip_scale);
   float dip_scale() const { return dip_scale_; }
   float page_scale_factor() const { return page_scale_factor_; }
 
   // Set the root layer scroll offset to |new_value|.
   void ScrollTo(const gfx::Vector2d& new_value);
 
@@ skipping 99 matching lines @@
   uint32_t next_compositor_id_;
 
   ParentCompositorDrawConstraints external_draw_constraints_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserViewRenderer);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_