cc : Move screen space scale factor to root transform node

cc/trees/layer_tree_host_common_unittest.cc

Index: cc/trees/layer_tree_host_common_unittest.cc
diff --git a/cc/trees/layer_tree_host_common_unittest.cc b/cc/trees/layer_tree_host_common_unittest.cc
index 3ede7ca293014ad40a051ff4ad02ca728338caf9..2a13a16e21525aa8bf506b2cfb132628221244df 100644
--- a/cc/trees/layer_tree_host_common_unittest.cc
+++ b/cc/trees/layer_tree_host_common_unittest.cc
@@ -1281,7 +1281,8 @@ TEST_F(LayerTreeHostCommonTest, TransformAboveRootLayer) {
     inputs.property_trees->needs_rebuild = true;
     LayerTreeHostCommon::CalculateDrawPropertiesForTesting(&inputs);
     gfx::Transform device_scaled_translate = translate;
-    device_scaled_translate.Scale(device_scale_factor, device_scale_factor);
+    device_scaled_translate.matrix().postScale(device_scale_factor,
+                                               device_scale_factor, 1.f);
     EXPECT_TRANSFORMATION_MATRIX_EQ(
         device_scaled_translate,
         root->draw_properties().target_space_transform);
@@ -1304,7 +1305,8 @@ TEST_F(LayerTreeHostCommonTest, TransformAboveRootLayer) {
     inputs.property_trees->needs_rebuild = true;
     LayerTreeHostCommon::CalculateDrawPropertiesForTesting(&inputs);
     gfx::Transform page_scaled_translate = translate;
-    page_scaled_translate.Scale(page_scale_factor, page_scale_factor);
+    page_scaled_translate.matrix().postScale(page_scale_factor,
+                                             page_scale_factor, 1.f);
     EXPECT_TRANSFORMATION_MATRIX_EQ(
         page_scaled_translate, root->draw_properties().target_space_transform);
     EXPECT_TRANSFORMATION_MATRIX_EQ(