SPv2: Add support for tracking raster paint invalidations in testing.

third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h

Index: third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h b/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
index 701f218b0221f7ade9a2b928a71e4879f64903da..6f2e48dd9d08aefbcaf02ee0f7e17ab9d73da64f 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
@@ -8,6 +8,7 @@
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/paint/DisplayItem.h"
 #include "platform/graphics/paint/PaintChunkProperties.h"
+#include "platform/graphics/paint/PaintInvalidationTracking.h"
 #include "wtf/Allocator.h"
 #include "wtf/Optional.h"
 #include "wtf/Vector.h"
@@ -83,7 +84,7 @@ struct PaintChunk {
 
     // SPv2 only. Rectangles that need to be re-rasterized in this chunk, in the
     // coordinate space of the containing transform node.
-    Vector<FloatRect> rasterInvalidationRects;
+    Vector<PaintInvalidationInfo> rasterInvalidationRects;

[Xianzhu, 2016/09/30 00:47:00]

I suggest to keep this to still contain FloatRect, and create another field for
raster invalidation tracking, so that we don't need to allocate the additional
fields in the items of this vector when we are not tracking invalidations.

I think we should use "RasterInvalidation" instead of "PaintInvalidation" here.
We can distinguish them in SPv2.

[chrishtr, 2016/09/30 18:19:10]

Done.

 };
 
 inline bool operator==(const PaintChunk& a, const PaintChunk& b)