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

cc/resources/tile_manager_perftest.cc

Index: cc/resources/tile_manager_perftest.cc
diff --git a/cc/resources/tile_manager_perftest.cc b/cc/resources/tile_manager_perftest.cc
index 65ec4d8ff8ed1593c85926bcc3feaa2cc5724940..3aa04a27e50582a7118089f1efbc31d624391ee5 100644
--- a/cc/resources/tile_manager_perftest.cc
+++ b/cc/resources/tile_manager_perftest.cc
@@ -187,7 +187,7 @@
 
     std::vector<LayerImpl*> layers = CreateLayers(layer_count, 10);
     for (unsigned i = 0; i < layers.size(); ++i)
-      layers[i]->UpdateTiles(Occlusion());
+      layers[i]->UpdateTiles(NULL);
 
     timer_.Reset();
     do {
@@ -214,7 +214,7 @@
 
     std::vector<LayerImpl*> layers = CreateLayers(layer_count, 100);
     for (unsigned i = 0; i < layers.size(); ++i)
-      layers[i]->UpdateTiles(Occlusion());
+      layers[i]->UpdateTiles(NULL);
 
     int priority_count = 0;
     timer_.Reset();
@@ -251,7 +251,7 @@
     for (unsigned i = 0; i < layers.size(); ++i) {
       FakePictureLayerImpl* layer =
           static_cast<FakePictureLayerImpl*>(layers[i]);
-      layer->UpdateTiles(Occlusion());
+      layer->UpdateTiles(NULL);
       for (size_t j = 0; j < layer->GetTilings()->num_tilings(); ++j) {
         tile_manager()->InitializeTilesWithResourcesForTesting(
             layer->GetTilings()->tiling_at(j)->AllTilesForTesting());
@@ -286,7 +286,7 @@
     for (unsigned i = 0; i < layers.size(); ++i) {
       FakePictureLayerImpl* layer =
           static_cast<FakePictureLayerImpl*>(layers[i]);
-      layer->UpdateTiles(Occlusion());
+      layer->UpdateTiles(NULL);
       for (size_t j = 0; j < layer->GetTilings()->num_tilings(); ++j) {
         tile_manager()->InitializeTilesWithResourcesForTesting(
             layer->GetTilings()->tiling_at(j)->AllTilesForTesting());
@@ -396,7 +396,7 @@
       BeginFrameArgs args = CreateBeginFrameArgsForTesting();
       host_impl_.UpdateCurrentBeginFrameArgs(args);
       for (unsigned i = 0; i < layers.size(); ++i)
-        layers[i]->UpdateTiles(Occlusion());
+        layers[i]->UpdateTiles(NULL);
 
       GlobalStateThatImpactsTilePriority global_state(GlobalStateForTest());
       tile_manager()->ManageTiles(global_state);