[webkit-reviews] review requested: [Bug 16171] [CAIRO] Canvas does not support globalAlpha : [Attachment 23090] Canvas globalAlpha

[bugzilla-daemon at webkit.org]

Dirk Schulze <vbs85 at gmx.de> has asked  for review:
Bug 16171: [CAIRO] Canvas does not support globalAlpha
https://bugs.webkit.org/show_bug.cgi?id=16171

Attachment 23090: Canvas globalAlpha
https://bugs.webkit.org/attachment.cgi?id=23090&action=edit

------- Additional Comments from Dirk Schulze <vbs85 at gmx.de>
The same patch as before, but replaced cairo_mask with cairo_paint_with_alpha.
Makes it 50% faster for strokes. 
I haven't chosen a common globalAlpha because of speed. The speed between the
drawings can differ up to 300%.
I choose the fastest way for every drawing operation. (fill/stroke with/without
globalAlpha)