[SPv2] Defer decision of raster invalidation after paint for changes z-index, transform, etc.

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 1bbda6742d97664b95a629c4ceccf289048d1ef6..701f218b0221f7ade9a2b928a71e4879f64903da 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintChunk.h
@@ -10,6 +10,7 @@
 #include "platform/graphics/paint/PaintChunkProperties.h"
 #include "wtf/Allocator.h"
 #include "wtf/Optional.h"
+#include "wtf/Vector.h"
 #include <iosfwd>
 
 namespace blink {
@@ -101,6 +102,23 @@ inline bool operator!=(const PaintChunk& a, const PaintChunk& b)
     return !(a == b);
 }
 
+inline bool chunkLessThanIndex(const PaintChunk& chunk, size_t index)
+{
+    return chunk.endIndex <= index;
+}
+
+inline Vector<PaintChunk>::iterator findChunkInVectorByDisplayItemIndex(Vector<PaintChunk>& chunks, size_t index)
+{
+    auto chunk = std::lower_bound(chunks.begin(), chunks.end(), index, chunkLessThanIndex);
+    DCHECK(chunk == chunks.end() || (index >= chunk->beginIndex && index < chunk->endIndex));
+    return chunk;
+}
+
+inline Vector<PaintChunk>::const_iterator findChunkInVectorByDisplayItemIndex(const Vector<PaintChunk>& chunks, size_t index)
+{
+    return findChunkInVectorByDisplayItemIndex(const_cast<Vector<PaintChunk>&>(chunks), index);
+}
+
 // Redeclared here to avoid ODR issues.
 // See platform/testing/PaintPrinters.h.
 void PrintTo(const PaintChunk&, std::ostream*);