cc: Merge LayerTree into the LayerTreeHost.

cc/trees/layer_tree_host_pixeltest_filters.cc

Index: cc/trees/layer_tree_host_pixeltest_filters.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_filters.cc b/cc/trees/layer_tree_host_pixeltest_filters.cc
index a4386cbd58db4f8c8cc5f783b0318d549c26c788..5190efd4ac0ad4b5d7674fec844b891d93687129 100644
--- a/cc/trees/layer_tree_host_pixeltest_filters.cc
+++ b/cc/trees/layer_tree_host_pixeltest_filters.cc
@@ -171,7 +171,7 @@ class LayerTreeHostFiltersScaledPixelTest
   }
 
   void SetupTree() override {
-    layer_tree()->SetDeviceScaleFactor(device_scale_factor_);
+    layer_tree_host()->SetDeviceScaleFactor(device_scale_factor_);
     LayerTreePixelTest::SetupTree();
   }
 
@@ -1070,7 +1070,7 @@ class BackgroundFilterWithDeviceScaleFactorTest
   }
 
   void SetupTree() override {
-    layer_tree()->SetDeviceScaleFactor(device_scale_factor_);
+    layer_tree_host()->SetDeviceScaleFactor(device_scale_factor_);
     LayerTreeHostFiltersPixelTest::SetupTree();
   }