[SPInvalidation] Use GeometryMapper in PaintLayerClipper for paint.

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

Index: third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.h b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.h
index 85f619141912be601892c52362b824a816f8f0c0..6ed23d3100e503579cf54c69b54a4915df511514 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/GeometryMapper.h
@@ -53,7 +53,10 @@ struct PrecomputedDataForAncestor {
 // TODO(chrishtr): take effect tree into account.
 class PLATFORM_EXPORT GeometryMapper {
  public:
-  GeometryMapper() {}
+  static std::unique_ptr<GeometryMapper> create() {
+    return WTF::wrapUnique(new GeometryMapper());
+  }
+
   // The runtime of m calls among localToAncestorVisualRect, localToAncestorRect
   // or ancestorToLocalRect with the same |ancestorState| parameter is
   // guaranteed to be O(n + m), where n is the number of transform and clip
@@ -143,6 +146,9 @@ class PLATFORM_EXPORT GeometryMapper {
 
   void clearCache();
 
+ protected:
+  GeometryMapper() {}
+
  private:
   // The internal methods do the same things as their public counterparts, but
   // take an extra |success| parameter which indicates if the function is