gfx: Make conversions from Size to SizeF be explicit.

cc/trees/layer_tree_impl_unittest.cc

Index: cc/trees/layer_tree_impl_unittest.cc
diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index 34d26d5f3b69f736bab4df04f341244a7875d1c1..5f60c21d3273a236e791e3713e6b1fc247a399ac 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -116,7 +116,7 @@ TEST_F(LayerTreeImplTest, UpdateViewportAndHitTest) {
   host_impl->active_tree()->SetRootLayer(root.Pass());
   host_impl->UpdateNumChildrenAndDrawPropertiesForActiveTree();
   EXPECT_EQ(
-      gfx::RectF(bounds),
+      gfx::RectF(gfx::SizeF(bounds)),
       host_impl->active_tree()->property_trees()->clip_tree.ViewportClip());
   EXPECT_EQ(gfx::Rect(bounds),
             host_impl->RootLayer()->visible_rect_from_property_trees());
@@ -126,7 +126,7 @@ TEST_F(LayerTreeImplTest, UpdateViewportAndHitTest) {
   gfx::Point test_point(51, 51);
   host_impl->active_tree()->FindLayerThatIsHitByPoint(test_point);
   EXPECT_EQ(
-      gfx::RectF(new_bounds),
+      gfx::RectF(gfx::SizeF(new_bounds)),
       host_impl->active_tree()->property_trees()->clip_tree.ViewportClip());
   EXPECT_EQ(gfx::Rect(new_bounds),
             host_impl->RootLayer()->visible_rect_from_property_trees());
@@ -1493,8 +1493,8 @@ TEST_F(LayerTreeImplTest,
 
   float device_scale_factor = 3.f;
   float page_scale_factor = 5.f;
-  gfx::Size scaled_bounds_for_root = gfx::ToCeiledSize(
-      gfx::ScaleSize(root->bounds(), device_scale_factor * page_scale_factor));
+  gfx::Size scaled_bounds_for_root = gfx::ScaleToCeiledSize(
+      root->bounds(), device_scale_factor * page_scale_factor);
   host_impl().SetViewportSize(scaled_bounds_for_root);
 
   host_impl().SetDeviceScaleFactor(device_scale_factor);
@@ -1952,8 +1952,8 @@ TEST_F(LayerTreeImplTest, SelectionBoundsForScaledLayers) {
 
   float device_scale_factor = 3.f;
   float page_scale_factor = 5.f;
-  gfx::Size scaled_bounds_for_root = gfx::ToCeiledSize(
-      gfx::ScaleSize(root->bounds(), device_scale_factor * page_scale_factor));
+  gfx::Size scaled_bounds_for_root = gfx::ScaleToCeiledSize(
+      root->bounds(), device_scale_factor * page_scale_factor);
   host_impl().SetViewportSize(scaled_bounds_for_root);
 
   host_impl().SetDeviceScaleFactor(device_scale_factor);