Move layer repaint rects into a map. Since many layers aren't self-painting, they're wasting space holding those rects. In addition, once we start caching rects for RenderLayerModelObjects that don't have layers (i.e., everyone using a LayoutRepainter right now), then we'll want to have a common structure.
Created attachment 317728 [details]
Attachment 317728 [details] did not pass style-queue:
ERROR: Source/WebCore/rendering/RenderLayerModelObject.h:33: One space before end of line comments [whitespace/comments] 
ERROR: Source/WebCore/rendering/RenderLayerModelObject.h:35: The parameter name "geometryMap" adds no information, so it should be removed. [readability/parameter_name] 
Total errors found: 2 in 6 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Landed in r220479.