Reland of: cc: Add occlusion checker as a fixed view of occlusion tracker.

cc/trees/occlusion_tracker_unittest.cc

 // Copyright 2012 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/occlusion_tracker.h"
 
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/base/math_util.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_impl.h"
@@ skipping 67 matching lines @@
 
 template <typename LayerType>
 class TestOcclusionTrackerWithClip : public TestOcclusionTracker<LayerType> {
  public:
   explicit TestOcclusionTrackerWithClip(const gfx::Rect& viewport_rect)
       : TestOcclusionTracker<LayerType>(viewport_rect) {}
 
   bool OccludedLayer(const LayerType* layer,
                      const gfx::Rect& content_rect) const {
     DCHECK(layer->visible_content_rect().Contains(content_rect));
+    EXPECT_EQ(
+        this->Occluded(
+            layer->render_target(), content_rect, layer->draw_transform()),
+        this->GetCurrentOcclusionForLayer(layer->draw_transform())
+            .IsOccluded(content_rect));
     return this->Occluded(
         layer->render_target(), content_rect, layer->draw_transform());
   }
 
   // Gives an unoccluded sub-rect of |content_rect| in the content space of the
   // layer. Simple wrapper around UnoccludedContentRect.
   gfx::Rect UnoccludedLayerContentRect(const LayerType* layer,
                                        const gfx::Rect& content_rect) const {
     DCHECK(layer->visible_content_rect().Contains(content_rect));
     return this->UnoccludedContentRect(content_rect, layer->draw_transform());
@@ skipping 3207 matching lines @@
     EXPECT_EQ(gfx::Rect(),
               occlusion.UnoccludedSurfaceContentRect(
                   surface, gfx::Rect(80, 70, 50, 50)));
   }
 };
 
 ALL_OCCLUSIONTRACKER_TEST(OcclusionTrackerTestUnoccludedSurfaceQuery)
 
 }  // namespace
 }  // namespace cc