Move LayerSorter to exist locally only in layer_tree_host_common

cc/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/occlusion_tracker.h"
 
 #include <public/WebFilterOperation.h>
 #include <public/WebFilterOperations.h>
 
 #include "cc/layer.h"
@@ skipping 260 matching lines @@
         WebFilterOperations filters;
         filters.append(WebFilterOperation::createGrayscaleFilter(0.5));
         layer->setFilters(filters);
         return layer;
     }
 
     void calcDrawEtc(TestContentLayerImpl* root)
     {
         DCHECK(root == m_root.get());
         int dummyMaxTextureSize = 512;
-        LayerSorter layerSorter;
 
         DCHECK(!root->renderSurface());
 
-        LayerTreeHostCommon::calculateDrawProperties(root, root->bounds(), 1, 1, &layerSorter, dummyMaxTextureSize, m_renderSurfaceLayerListImpl);
+        LayerTreeHostCommon::calculateDrawProperties(root, root->bounds(), 1, 1, dummyMaxTextureSize, m_renderSurfaceLayerListImpl);
 
         m_layerIterator = m_layerIteratorBegin = Types::TestLayerIterator::begin(&m_renderSurfaceLayerListImpl);
     }
 
     void calcDrawEtc(TestContentLayer* root)
     {
         DCHECK(root == m_root.get());
         int dummyMaxTextureSize = 512;
 
         DCHECK(!root->renderSurface());
@@ skipping 2777 matching lines @@
 
         EXPECT_EQ(gfx::Rect(gfx::Point(), trackingSize).ToString(), occlusion.occlusionInScreenSpace().ToString());
         EXPECT_EQ(gfx::Rect(gfx::Point(), trackingSize).ToString(), occlusion.occlusionInTargetSurface().ToString());
     }
 };
 
 ALL_OCCLUSIONTRACKER_TEST(OcclusionTrackerTestMinimumTrackingSize);
 
 }  // namespace
 }  // namespace cc