Rename WindowTreeHost functions to indicate pixels/dips.

ash/host/ash_window_tree_host_x11.cc

Index: ash/host/ash_window_tree_host_x11.cc
diff --git a/ash/host/ash_window_tree_host_x11.cc b/ash/host/ash_window_tree_host_x11.cc
index ac093955191830eb37f4d0c111ae86d900834a19..82b0ebc7b28a6632c139b9fc33864c8fde2f8900 100644
--- a/ash/host/ash_window_tree_host_x11.cc
+++ b/ash/host/ash_window_tree_host_x11.cc
@@ -141,8 +141,9 @@ gfx::Transform AshWindowTreeHostX11::GetInverseRootTransform() const {
   return transformer_helper_.GetInverseTransform();
 }
 
-void AshWindowTreeHostX11::UpdateRootWindowSize(const gfx::Size& host_size) {
-  transformer_helper_.UpdateWindowSize(host_size);
+void AshWindowTreeHostX11::UpdateRootWindowSizeInPixels(
+    const gfx::Size& host_size_in_pixels) {
+  transformer_helper_.UpdateWindowSize(host_size_in_pixels);
 }
 
 void AshWindowTreeHostX11::OnCursorVisibilityChangedNative(bool show) {