[InputEvent] Introduce |StaticRange| and use in |InputEvent::getRanges()|

third_party/WebKit/Source/core/events/InputEvent.idl

 // Copyright 2016 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.
 
 // https://w3c.github.io/editing/input-events.html
 
 [
     Constructor(DOMString type, optional InputEventInit eventInitDict),
     RuntimeEnabled=InputEvent,
 ] interface InputEvent : UIEvent {
     readonly attribute DOMString inputType;
     readonly attribute DOMString data;
     readonly attribute boolean isComposing;
-    // TODO(chongz): Return StaticRange.
-    sequence<Range> getRanges();
+    sequence<StaticRange> getRanges();
 };