Convert the coordinates in WebInputEvent To Viewport in InputRouter

content/browser/renderer_host/input/input_router.h

 // Copyright 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 CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_H_
 
 #include "base/basictypes.h"
 #include "content/browser/renderer_host/event_with_latency_info.h"
 #include "content/common/input/input_event_ack_state.h"
@@ skipping 37 matching lines @@
   // the site has a mobile-friendly viewport).
   virtual void NotifySiteIsMobileOptimized(bool is_mobile_optimized) = 0;
 
   // Request a notification from the input router when all events have been
   // fully dispatched and there are no longer any pending events.
   // Note: This may trigger a synchronous notification if the router is empty.
   virtual void RequestNotificationWhenFlushed() = 0;
 
   // Whether there are any events pending dispatch to or ack from the renderer.
   virtual bool HasPendingEvents() const = 0;
+
+  // A scale factor to scale the coordinate in WebInputEvent from DIP
+  // to viewport.
+  virtual void SetDeviceScaleFactor(float device_scale_factor) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_INPUT_ROUTER_H_