Fix Windows compile error with cherry-pick.

content/renderer/input/render_widget_input_handler_delegate.h

 // Copyright 2015 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_INPUT_RENDER_WIDGET_INPUT_HANDLER_DELEGATE_H_
 #define CONTENT_RENDERER_INPUT_RENDER_WIDGET_INPUT_HANDLER_DELEGATE_H_
 
 #include <memory>
 
 #include "content/common/content_export.h"
@@ skipping 55 matching lines @@
   // Call this if virtual keyboard should be displayed, e.g. after a tap on an
   // input field on mobile. Note that we do this just by setting a bit in
   // text input state and update it to the browser such that browser process can
   // be up to date when showing virtual keyboard.
   virtual void ShowVirtualKeyboard() = 0;
 
   // Send an update of text input state to the browser process.
   virtual void UpdateTextInputState() = 0;
 
   // Clear the text input state.
-  virtual void ClearTextInputState() = 0;
+  virtual void ClearTextInputState() {}
 
   // Notifies that a gesture event is about to be handled.
   // Returns true if no further handling is needed. In that case, the event
   // won't be sent to WebKit.
   virtual bool WillHandleGestureEvent(const blink::WebGestureEvent& event) = 0;
 
   // Notifies that a mouse event is about to be handled.
   // Returns true if no further handling is needed. In that case, the event
   // won't be sent to WebKit or trigger DidHandleMouseEvent().
   virtual bool WillHandleMouseEvent(const blink::WebMouseEvent& event) = 0;
 
  protected:
   virtual ~RenderWidgetInputHandlerDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_INPUT_RENDER_WIDGET_INPUT_HANDLER_DELEGATE_H_