Hook up style invalidation for CSS Paint API.

third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h

Index: third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h
diff --git a/third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h b/third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h
index cf4208b9f10fb66feb185b48dc15ff0d49afca39..396da9971798fd09c98b6f7e44a883d4e1e58983 100644
--- a/third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h
+++ b/third_party/WebKit/Source/core/style/StyleRareNonInheritedData.h
@@ -153,6 +153,8 @@ public:
 
     Vector<String> m_callbackSelectors;
 
+    Vector<Persistent<StyleImage>> m_paintImages;

[rune, 2016/04/29 08:06:37]

It's a bit unfortunate that we store these in the computed style as they're only
needed right after style resolution for diffing. I realize the
StyleResolverState is gone before we do the diff, otherwise that could be a
place to store them. Is the rationale that looking up the known image properties
in the diff like you did before is more expensive? Or that this is just cleaner?

[ikilpatrick, 2016/04/29 22:42:01]

Both, but primarily (slightly) less expensive. Now we just have an empty vector
check, as opposed to walking through the list of all images.

It's not a big gain so can switch back if you like? But seemed better this way.

+
     StyleContentAlignmentData m_alignContent;
     StyleSelfAlignmentData m_alignItems;
     StyleSelfAlignmentData m_alignSelf;