MockQC stops create its own RP and MockOcclusionTracker

cc/test/mock_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_MOCK_OCCLUSION_TRACKER_H_
 #define CC_TEST_MOCK_OCCLUSION_TRACKER_H_
 
 #include "cc/trees/occlusion_tracker.h"
 
 namespace cc {
 
 template <typename LayerType>
 class MockOcclusionTracker : public OcclusionTracker<LayerType> {
   // This class is used for testing only. It fakes just enough information to
   // calculate unoccluded content rect and unoccluded contributing surface
   // content rect. It calls the helper function of occlusion tracker to avoid
   // DCHECKs since testing environment won't be set up properly to pass those.
  public:
+  MockOcclusionTracker()
+      : OcclusionTracker<LayerType>(gfx::Rect(0, 0, 1000, 1000)) {
+    typename OcclusionTracker<LayerType>::StackObject stack_obj;
+    OcclusionTracker<LayerType>::stack_.push_back(stack_obj);
+    OcclusionTracker<LayerType>::stack_.push_back(stack_obj);
+  }
+
   explicit MockOcclusionTracker(const gfx::Rect& screen_scissor_rect)
       : OcclusionTracker<LayerType>(screen_scissor_rect) {
     typename OcclusionTracker<LayerType>::StackObject stack_obj;
     OcclusionTracker<LayerType>::stack_.push_back(stack_obj);
     OcclusionTracker<LayerType>::stack_.push_back(stack_obj);
   }
 
   void set_occluded_target_rect(const gfx::Rect& occluded) {
     OcclusionTracker<LayerType>::stack_.back().occlusion_from_inside_target =
         occluded;
   }
 
   void set_occluded_target_rect_for_contributing_surface(
       const gfx::Rect& occluded) {
     OcclusionTracker<
         LayerType>::stack_[OcclusionTracker<LayerType>::stack_.size() - 2]
         .occlusion_from_inside_target = occluded;
   }
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_MOCK_OCCLUSION_TRACKER_H_