Convert the coordinates in WebInputEvent To Viewport in InputRouter

content/browser/renderer_host/input/input_router.h

Index: content/browser/renderer_host/input/input_router.h
diff --git a/content/browser/renderer_host/input/input_router.h b/content/browser/renderer_host/input/input_router.h
index 186022feba8dac8adb4b544497ae3774ed696410..b0b7ff7034c0d97dbf36533878e62e18f55012a6 100644
--- a/content/browser/renderer_host/input/input_router.h
+++ b/content/browser/renderer_host/input/input_router.h
@@ -55,6 +55,10 @@ class InputRouter : public IPC::Listener {
 
   // 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