cc : Fix transform calculation bug while calculating clip rects

cc/trees/draw_property_utils.cc

 // Copyright 2014 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 "cc/trees/draw_property_utils.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 61 matching lines @@
           effect_tree.Node(clip_node->target_effect_id);
       ConcatInverseSurfaceContentsScale(source_node, &clip_to_target);
       *clip_rect_in_target_space =
           MathUtil::MapClippedRect(clip_to_target, clip_from_clip_node);
     } else {
       return false;
     }
   } else {
     if (property_trees->ComputeTransformFromTarget(
             target_node_id, clip_node->target_effect_id, &clip_to_target)) {
+      const EffectNode* source_node =
+          effect_tree.Node(clip_node->target_effect_id);
+      PostConcatSurfaceContentsScale(target_effect_node, &clip_to_target);
+      ConcatInverseSurfaceContentsScale(source_node, &clip_to_target);

[jaydasika, 2017/02/24 01:08:39]

We do the same thing in ComputeClips when we calculate the inverse transform
between two render surfaces, it somehow got missed here.

https://cs.chromium.org/chromium/src/cc/trees/draw_property_utils.cc?q=Comput...

       *clip_rect_in_target_space =
           MathUtil::ProjectClippedRect(clip_to_target, clip_from_clip_node);
     } else {
       return false;
     }
   }
   return true;
 }
 
 struct ConditionalClip {
@@ skipping 1417 matching lines @@
 void UpdateElasticOverscroll(PropertyTrees* property_trees,
                              const Layer* overscroll_elasticity_layer,
                              const gfx::Vector2dF& elastic_overscroll) {
   UpdateElasticOverscrollInternal(property_trees, overscroll_elasticity_layer,
                                   elastic_overscroll);
 }
 
 }  // namespace draw_property_utils
 
 }  // namespace cc