Use IDL union types for CanvasRenderingContext2D.{fill,stroke}Style

Source/core/html/canvas/CanvasRenderingContext2D.idl

Index: Source/core/html/canvas/CanvasRenderingContext2D.idl
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.idl b/Source/core/html/canvas/CanvasRenderingContext2D.idl
index 8f575e2df9a4ed71a9f72d90680c0d5fceb16565..5b315bd7977bb52be5e58e15a5b85afe74e5277d 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.idl
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.idl
@@ -63,9 +63,8 @@ enum CanvasFillRule { "nonzero", "evenodd" };
     [MeasureAs=UnprefixedImageSmoothingEnabled] attribute boolean imageSmoothingEnabled;
 
     // colors and styles (see also the CanvasDrawingStyles interface)
-    // FIXME: Use union types when supported: http://crbug.com/372891

[fs, 2014/11/24 13:20:24]

This bug seems to have some sort Restrict* label set (or at least I couldn't
access it).

[Jens Widell, 2014/11/24 13:38:24]

That's an unrelated crash bug (CC:ed oilpan-reviews@, so I could randomly see
it.)

The bug that ought to have been referenced here is: http://crbug.com/240176

[fs, 2014/11/24 13:49:07]

Thanks, that's the info I was probing for. As discussed elsewhere, I'll replace
the ref to the above (240176) with 430337.

-    [Custom] attribute object strokeStyle; // (default black)
-    [Custom] attribute object fillStyle; // (default black)
+    attribute (DOMString or CanvasGradient or CanvasPattern) strokeStyle; // (default black)
+    attribute (DOMString or CanvasGradient or CanvasPattern) fillStyle; // (default black)
     CanvasGradient createLinearGradient(float x0, float y0, float x1, float y1);
     [RaisesException] CanvasGradient createRadialGradient(float x0, float y0, float r0, float x1, float y1, float r1);
     [RaisesException] CanvasPattern createPattern(CanvasImageSource image, DOMString? repetitionType);