Do not clip inside OcclusionTracker: Contributing Surfaces Edition.

cc/test/test_occlusion_tracker.h

 // 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.
 
 #ifndef CC_TEST_TEST_OCCLUSION_TRACKER_H_
 #define CC_TEST_TEST_OCCLUSION_TRACKER_H_
 
 #include "cc/layers/render_surface.h"
 #include "cc/layers/render_surface_impl.h"
 #include "cc/trees/occlusion_tracker.h"
 
 namespace cc {
 
 // A subclass to expose the total current occlusion.
 template <typename LayerType>
 class TestOcclusionTracker : public OcclusionTracker<LayerType> {
  public:
   explicit TestOcclusionTracker(const gfx::Rect& screen_scissor_rect)
       : OcclusionTracker<LayerType>(screen_scissor_rect) {}
 
   Region occlusion_from_inside_target() const {
     return OcclusionTracker<LayerType>::stack_.back()
         .occlusion_from_inside_target;
   }
   Region occlusion_from_outside_target() const {
     return OcclusionTracker<LayerType>::stack_.back()
         .occlusion_from_outside_target;
   }
 
+  Region occlusion_on_contributing_surface_from_inside_target() const {
+    size_t stack_size = OcclusionTracker<LayerType>::stack_.size();
+    if (stack_size < 2)
+      return Region();
+    return OcclusionTracker<LayerType>::stack_[stack_size - 2]
+        .occlusion_from_inside_target;
+  }
+  Region occlusion_on_contributing_surface_from_outside_target() const {
+    size_t stack_size = OcclusionTracker<LayerType>::stack_.size();
+    if (stack_size < 2)
+      return Region();
+    return OcclusionTracker<LayerType>::stack_[stack_size - 2]
+        .occlusion_from_outside_target;
+  }
+
   void set_occlusion_from_outside_target(const Region& region) {
     OcclusionTracker<LayerType>::stack_.back().occlusion_from_outside_target =
         region;
   }
   void set_occlusion_from_inside_target(const Region& region) {
     OcclusionTracker<LayerType>::stack_.back().occlusion_from_inside_target =
         region;
   }
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_TEST_OCCLUSION_TRACKER_H_