Adds filter support for offscreen canvas

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 28 matching lines @@
 
     // 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")
     attribute unrestricted double miterLimit; // (default 10)
 
     // dashed lines
     void setLineDash(sequence<unrestricted double> dash);
     sequence<unrestricted double> getLineDash();
-    attribute unrestricted double lineDashOffset; 
+    attribute unrestricted double lineDashOffset;
 
     // state
     void save(); // push state on state stack
     void restore(); // pop state stack and restore state
 
     // transformations (default transform is the identity matrix)
     void scale(unrestricted double x, unrestricted double y);
     void rotate(unrestricted double angle);
     void translate(unrestricted double x, unrestricted double y);
     void transform(unrestricted double a, unrestricted double b, unrestricted double c, unrestricted double d, unrestricted double e, unrestricted double f);
@@ skipping 10 matching lines @@
     attribute unrestricted double shadowBlur;
     attribute DOMString shadowColor;
 
     // 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);
 
-    [Exposed=Window] attribute DOMString filter;
+    attribute DOMString filter;
 };
 
 OffscreenCanvasRenderingContext2D implements CanvasPathMethods;