cc: Pass Occlusion instead of OcclusionTracker to LayerImpls

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index d8b8b3ec06ba2fb3d47445cbcacdea08beea516a..be5967c3c925c3df4287b6a76b06f2146985a556 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -1628,7 +1628,7 @@ class EvictionTestLayerImpl : public LayerImpl {
   virtual ~EvictionTestLayerImpl() {}
 
   virtual void AppendQuads(RenderPass* render_pass,
-                           const OcclusionTracker<LayerImpl>& occlusion_tracker,
+                           const Occlusion& occlusion_in_content_space,
                            AppendQuadsData* append_quads_data) override {
     ASSERT_TRUE(has_texture_);
     ASSERT_NE(0u, layer_tree_impl()->resource_provider()->num_resources());