CanvasPathMethods should be shared with CRC2D and Path2D

Source/core/html/canvas/CanvasPathMethods.idl

+// Copyright 2014 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.
+
+[
+    NoInterfaceObject
+] interface CanvasPathMethods {
+
+    void closePath();
+    void moveTo(float x, float y);
+    void lineTo(float x, float y);
+    void quadraticCurveTo(float cpx, float cpy, float x, float y);
+    void bezierCurveTo(float cp1x, float cp1y, float cp2x, float cp2y, float x, float y);
+    [RaisesException] void arcTo(float x1, float y1, float x2, float y2, float radius);
+    void rect(float x, float y, float width, float height);
+    [RaisesException] void arc(float x, float y, float radius, float startAngle, float endAngle, [Default=Undefined] optional boolean anticlockwise);
+    [RaisesException] void ellipse(float x, float y, float radiusX, float radiusY, float rotation, float startAngle, float endAngle, [Default=Undefined] optional boolean anticlockwise);
+};