[SPv1] Fix return value for "fallback" case of inverted clips.

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

 // 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.
 
 #include "platform/graphics/paint/GeometryMapper.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/LayoutRect.h"
 
 namespace blink {
@@ skipping 101 matching lines @@
   }
 
   const auto& transform_matrix = LocalToAncestorMatrixInternal(
       local_state.Transform(), ancestor_state.Transform(), success);
   if (!success) {
     return;
   }
 
   FloatRect mapped_rect = transform_matrix.MapRect(rect_to_map.Rect());
 
-  FloatClipRect clip_rect =
+  const FloatClipRect& clip_rect =
       LocalToAncestorClipRectInternal(local_state.Clip(), ancestor_state.Clip(),
                                       ancestor_state.Transform(), success);
 
   if (success) {
     // This is where we propagate the rounded-ness of |clipRect| to
     // |rectToMap|.
     rect_to_map = clip_rect;
     rect_to_map.Intersect(mapped_rect);
   } else if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
     // On SPv1 we may fail when the paint invalidation container creates an
     // overflow clip (in ancestorState) which is not in localState of an
     // out-of-flow positioned descendant. See crbug.com/513108 and layout test
     // compositing/overflow/handle-non-ancestor-clip-parent.html (run with
     // --enable-prefer-compositing-to-lcd-text) for details.
     // Ignore it for SPv1 for now.
     success = true;
+    rect_to_map.SetRect(mapped_rect);
   }
 }
 
 void GeometryMapper::SlowLocalToAncestorVisualRectWithEffects(
     const PropertyTreeState& local_state,
     const PropertyTreeState& ancestor_state,
     FloatClipRect& mapping_rect,
     bool& success) {
   PropertyTreeState last_transform_and_clip_state(local_state.Transform(),
                                                   local_state.Clip(), nullptr);
@@ skipping 57 matching lines @@
     return;
 
   const auto& transform_matrix =
       LocalToAncestorMatrix(local_transform_node, ancestor_transform_node);
   DCHECK(transform_matrix.IsInvertible());
 
   // TODO(chrishtr): Cache the inverse?
   rect = transform_matrix.Inverse().MapRect(rect);
 }
 
-FloatClipRect GeometryMapper::LocalToAncestorClipRect(
+const FloatClipRect& GeometryMapper::LocalToAncestorClipRect(
     const PropertyTreeState& local_state,
     const PropertyTreeState& ancestor_state) {
   bool success = false;
-  FloatClipRect result =
+  const FloatClipRect& result =
       LocalToAncestorClipRectInternal(local_state.Clip(), ancestor_state.Clip(),
                                       ancestor_state.Transform(), success);
 
   DCHECK(success);
 
   return result;
 }
 
 const FloatClipRect& GeometryMapper::SourceToDestinationClipRect(
     const PropertyTreeState& source_state,
@@ skipping 239 matching lines @@
     const TransformPaintPropertyNode*,
     const TransformPaintPropertyNode*);
 template const ClipPaintPropertyNode* GeometryMapper::LowestCommonAncestor(
     const ClipPaintPropertyNode*,
     const ClipPaintPropertyNode*);
 template const ScrollPaintPropertyNode* GeometryMapper::LowestCommonAncestor(
     const ScrollPaintPropertyNode*,
     const ScrollPaintPropertyNode*);
 
 }  // namespace blink