Fix 2D canvas state persistency after OffscreenCanvas.transferToImageBitmap

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.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.
 
 // Note: The official spec is WIP at wiki.whatwg.org/wiki/OffscreenCanvas.
 
 [
     Exposed=(Window,Worker),
     RuntimeEnabled=ExperimentalCanvasFeatures,
 ] interface OffscreenCanvasRenderingContext2D {
@@ skipping 11 matching lines @@
     void clearRect(unrestricted double x, unrestricted double y, unrestricted double width, unrestricted double height);
     void fillRect(unrestricted double x, unrestricted double y, unrestricted double width, unrestricted double height);
     void strokeRect(unrestricted double x, unrestricted double y, unrestricted double width, unrestricted double height);
 
     // Path API (See BaseRenderingContext2D)
     void beginPath();
     void fill(optional CanvasFillRule winding);
     void fill(Path2D path, optional CanvasFillRule winding);
     void stroke();
     void stroke(Path2D path);
+    void clip();
+    void clip(Path2D path);

[Stephen White, 2016/05/20 17:41:26]

Not sure I understand this change. Were these already implemented in Base, just
not exposed in the IDL?

 
     // drawing images
     [CallWith=ExecutionContext, RaisesException] void drawImage(CanvasImageSource image, unrestricted double x, unrestricted double y);
     [CallWith=ExecutionContext, RaisesException] void drawImage(CanvasImageSource image, unrestricted double x, unrestricted double y, unrestricted double width, unrestricted double height);
     [CallWith=ExecutionContext, RaisesException] void drawImage(CanvasImageSource image, unrestricted double sx, unrestricted double sy, unrestricted double sw, unrestricted double sh, unrestricted double dx, unrestricted double dy, unrestricted double dw, unrestricted double dh);
 
     // Line caps/joins
     attribute unrestricted double lineWidth; // (default 1)
     attribute DOMString lineCap; // "butt", "round", "square" (default "butt")
     attribute DOMString lineJoin; // "round", "bevel", "miter" (default "miter")
@@ skipping 24 matching lines @@
 
     // pixel manipulation
     [RaisesException] ImageData createImageData(ImageData imagedata);
     [RaisesException] ImageData createImageData(double sw, double sh);
     [RaisesException] ImageData getImageData(double sx, double sy, double sw, double sh);
     [RaisesException] void putImageData(ImageData imagedata, double dx, double dy);
     [RaisesException] void putImageData(ImageData imagedata, double dx, double dy, double dirtyX, double dirtyY, double dirtyWidth, double dirtyHeight);
 };
 
 OffscreenCanvasRenderingContext2D implements CanvasPathMethods;