Fix mouse wheel over-scrolls when display is scaled and scroll is paginated

content/renderer/render_view_impl.h

 // Copyright (c) 2012 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 CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 #define CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 367 matching lines @@
   void SetEditCommandForNextKeyEvent(const std::string& name,
                                      const std::string& value) override;
   void ClearEditCommands() override;
   const std::string& GetAcceptLanguages() const override;
 #if defined(OS_ANDROID)
   void UpdateBrowserControlsState(BrowserControlsState constraints,
                                   BrowserControlsState current,
                                   bool animate) override;
 #endif
   void ConvertViewportToWindowViaWidget(blink::WebRect* rect) override;
+  float GetOriginalDeviceScaleFactor() const override;
   gfx::RectF ElementBoundsInWindow(const blink::WebElement& element) override;
   bool HasAddedInputHandler() const override;
 
   bool uses_temporary_zoom_level() const { return uses_temporary_zoom_level_; }
 
   // Please do not add your stuff randomly to the end here. If there is an
   // appropriate section, add it there. If not, there are some random functions
   // nearer to the top you can add it to.
 
  protected:
@@ skipping 445 matching lines @@
   // use the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_IMPL_H_