[SVG] DisplayList-based patterns.

LayoutTests/svg/custom/absolute-root-position-masking.xhtml

Index: LayoutTests/svg/custom/absolute-root-position-masking.xhtml
diff --git a/LayoutTests/svg/custom/absolute-root-position-masking.xhtml b/LayoutTests/svg/custom/absolute-root-position-masking.xhtml
index 272e9685457016f38ddd90e8236800189e4e8749..14423e50ca3257047a4ccab816e97e5c43b8558b 100644
--- a/LayoutTests/svg/custom/absolute-root-position-masking.xhtml
+++ b/LayoutTests/svg/custom/absolute-root-position-masking.xhtml
@@ -4,10 +4,10 @@
 <svg:svg id="svg" width="300" height="300" style="position: absolute; top: 100px; left: 0px;">
     <svg:circle cx="300" cy="300" r="100" fill="blue" mask="url(#mask)"/>
     <svg:defs>
-        <svg:pattern id="pattern" width="600" height="600">
+        <svg:pattern id="pattern" width="600" height="600" patternUnits="userSpaceOnUse">

[Stephen White, 2014/10/22 15:11:26]

What's the reason for the change here? Should we (or do we) also have a test for
patternUnits="objectBoundingBox"?

[f(malita), 2014/10/22 16:23:46]

We have plenty of coverage for OBB, this (and the other test change) is just an
unrelated test fix: given the actual values, it is clear the intent is to use
userSpaceOnUse (600 in OBB units is pretty damn huge :).

The reason I've included it is that (at least before we landed tile clamping in
Skia) this would yield slightly different results due to different tile scaling.
Since we get to touch the baseline anyway, I figured we might as well fix the
test too.

With tile clamping in place though, I don't think there is a difference anymore.
Let me try to take these out (and fix the tests in a follow-up CL).

Done.

             <svg:rect fill="white" width="600" height="600" />
         </svg:pattern>
-        <svg:mask id="mask" width="600" height="600">
+        <svg:mask id="mask" width="600" height="600" maskUnits="userSpaceOnUse">
             <svg:rect fill="url(#pattern)" width="600" height="600" />
         </svg:mask>
     </svg:defs>