[InputEvent] Make StaticRange immutable and move tests to wpt

third_party/WebKit/Source/core/dom/StaticRange.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://garykac.github.io/staticrange/#interface-staticrange
 
 [
     Constructor,
     ConstructorCallWith=Document,
     Exposed=Window,
     RuntimeEnabled=InputEvent,
 ] interface StaticRange {
-    attribute Node startContainer;
-    attribute unsigned long startOffset;
-    attribute Node endContainer;
-    attribute unsigned long endOffset;
+    readonly attribute Node startContainer;
+    readonly attribute unsigned long startOffset;
+    readonly attribute Node endContainer;
+    readonly attribute unsigned long endOffset;
     readonly attribute boolean collapsed;
 
-    void setStart(Node node, unsigned long offset);
-    void setEnd(Node node, unsigned long offset);
-
-    [NewObject, RaisesException] Range toRange();
+    // TODO(chongz): Add back when the spec becomes stable.
+    // void setStart(Node node, unsigned long offset);
+    // void setEnd(Node node, unsigned long offset);
+    // [NewObject, RaisesException] Range toRange();
 };