Skip geometry mapping when source and destination spaces are equal

third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp

Index: third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp
index b4848056059cc6f5e8c8afdf7fff07cf037851f4..190cd2d5b9d3fb8fe1a874e38a677c258efc10f7 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.cpp
@@ -14,6 +14,10 @@ FloatRect GeometryMapper::mapToVisualRectInDestinationSpace(
     const PropertyTreeState& sourceState,
     const PropertyTreeState& destinationState,
     bool& success) {
+  if (sourceState == destinationState) {
+    success = true;
+    return rect;
+  }
   FloatRect result = localToVisualRectInAncestorSpace(
       rect, sourceState, destinationState, success);
   if (success)
@@ -27,6 +31,10 @@ FloatRect GeometryMapper::mapRectToDestinationSpace(
     const PropertyTreeState& sourceState,
     const PropertyTreeState& destinationState,
     bool& success) {
+  if (sourceState == destinationState) {
+    success = true;
+    return rect;
+  }
   FloatRect result =
       localToAncestorRect(rect, sourceState, destinationState, success);
   if (success)