Remove infinite clip in PaintArtifactCompositor.

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GeometryMapper_h
 #define GeometryMapper_h
 
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/paint/PropertyTreeState.h"
 #include "platform/transforms/TransformationMatrix.h"
@@ skipping 107 matching lines @@
                                 bool& success);
 
   // Returns the matrix used in |LocalToAncestorRect|. Sets |success| to false
   // iff |localTransformNode| is not equal to or a descendant of
   // |ancestorState.transform|.
   const TransformationMatrix& localToAncestorMatrix(
       const TransformPaintPropertyNode* localTransformNode,
       const PropertyTreeState& ancestorState,
       bool& success);
 
+  // Returns the "clip visual rect" between |localTransformState| and
+  // |ancestorState|. See above for the definition of "clip visual rect".
+  FloatRect localToAncestorClipRect(

[wkorman, 2016/12/29 19:20:40]

nit: this is only unit tested indirectly, may be worth adding a few specific
test(s) as we expose it as a public method, but not a big deal. 

[chrishtr, 2016/12/29 19:34:21]

Good idea. Done.

+      const PropertyTreeState& localTransformState,
+      const PropertyTreeState& ancestorState,
+      bool& success);
+
  private:
   // Used by mapToVisualRectInDestinationSpace() after fast mapping (assuming
   // destination is an ancestor of source) failed.
   FloatRect slowMapToVisualRectInDestinationSpace(
       const FloatRect&,
       const PropertyTreeState& sourceState,
       const PropertyTreeState& destinationState,
       bool& success);
 
   // Used by mapRectToDestinationSpace() after fast mapping (assuming
   // destination is an ancestor of source) failed.
   FloatRect slowMapRectToDestinationSpace(
       const FloatRect&,
       const PropertyTreeState& sourceState,
       const PropertyTreeState& destinationState,
       bool& success);
 
-  // Returns the "clip visual rect" between |localTransformState| and
-  // |ancestorState|. See above for the definition of "clip visual rect".
-  FloatRect localToAncestorClipRect(
-      const PropertyTreeState& localTransformState,
-      const PropertyTreeState& ancestorState,
-      bool& success);
-
   // Returns the precomputed data if already set, or adds and memoizes a new
   // PrecomputedDataForAncestor otherwise.
   PrecomputedDataForAncestor& getPrecomputedDataForAncestor(
       const PropertyTreeState&);
 
   // Returns the least common ancestor in the transform tree.
   static const TransformPaintPropertyNode* leastCommonAncestor(
       const TransformPaintPropertyNode*,
       const TransformPaintPropertyNode*);
 
   friend class GeometryMapperTest;
 
   HashMap<const TransformPaintPropertyNode*,
           std::unique_ptr<PrecomputedDataForAncestor>>
       m_data;
 
   const TransformationMatrix m_identity;
 
   DISALLOW_COPY_AND_ASSIGN(GeometryMapper);
 };
 
 }  // namespace blink
 
 #endif  // GeometryMapper_h