Add versions of stroke, fill, and clip that take a Path parameter.

Source/core/html/canvas/CanvasRenderingContext2D.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 62 matching lines @@
     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, boolean anticlockwise);
 
+    void fill(Path? path, optional CanvasWindingRule winding);

[jcgregorio, 2014/01/23 18:17:14]

The part that I'm unsure about is that if I need to add
[RuntimeEnabled=ExperimentalCanvasFeatures] here, since fill, stroke and clip
already exist in CanvasRenderingContext2D.

It appears that putting [RuntimeEnabled=ExperimentalCanvasFeatures] on the first
definition of a method, such as 'fill', will hide *all* definitions of 'fill'
behind the features flag, while not putting it first definition, but putting on
on the second or later definition of a method will cause all definitions to
*not* be hidden behind the features flag.

[Stephen White, 2014/01/23 19:17:06]

If so, that sounds like a bug in the RuntimeEnabled feature that should be fixed
before this is landed. Perhaps eseidel knows what's up here.

We definitely need to keep new API behind a flag, if it hasn't passed through
the Blink new feature launch process.

[eseidel, 2014/01/23 20:24:01]

RuntimeEnabled= is a bindings generation feature.  I'd bring it up with haraken
or nbarth.

[Nils Barth (inactive), 2014/01/29 06:59:17]

Thanks for raising this Eric, and thanks to Joe and Stephen for analysis!
This is a limitation of the current bindings generator,
and has actually come up another time recently.

I've opened a bug for this:
[RuntimeEnabled] on overloaded methods
https://code.google.com/p/chromium/issues/detail?id=339000

Likely won't get to this soon (compiler rewrite), but maybe end of Feb or in
March.

[jcgregorio, 2014/01/29 17:51:49]

Thanks for the update and good news about the rewrite, I wasn't looking forward
to doing any Perl :-)

Is this really a blocker for this CL, Path is already hidden behind a
RuntimeEnabled flag, even if fill(path, winding) isn't hidden, you could never
call it because you would never be able to create the needed Path object.

On 2014/01/29 06:59:17, Nils Barth wrote:

[jcgregorio, 2014/01/30 20:41:57]

Updated the .idl to have RuntimeEnabled=ExperimentalCanvasFeatures where
possible, and comments with a link to the crbug where it isn't possible.

On 2014/01/29 17:51:49, jcgregorio wrote:

[Nils Barth (inactive), 2014/01/31 00:42:38]

Thanks Joe - LGTM for IDL!

     void fill(optional CanvasWindingRule winding);
     void stroke();
+    void stroke(Path path);
+    void clip(Path? path, optional CanvasWindingRule winding);

[dshwang, 2014/01/23 21:17:17]

why "Path? path", instead of "Path path"?

The spec:
  void clip(Path path, optional CanvasFillRule fillRule = "nonzero");

[jcgregorio, 2014/01/29 17:51:49]

Done.

     void clip(optional CanvasWindingRule winding);
     boolean isPointInPath(float x, float y, optional CanvasWindingRule winding);
     boolean isPointInStroke(float x, float y);
 
     // text
     attribute DOMString font;
     attribute DOMString textAlign;
     attribute DOMString textBaseline;
 
     TextMetrics measureText(DOMString text);
@@ skipping 72 matching lines @@
     [RuntimeEnabled=ExperimentalCanvasFeatures] boolean drawCustomFocusRing(Element element);
 
     readonly attribute float webkitBackingStorePixelRatio;
 
     [ImplementedAs=imageSmoothingEnabled] attribute boolean webkitImageSmoothingEnabled;
     attribute boolean imageSmoothingEnabled;
 
     Canvas2DContextAttributes getContextAttributes();
 };