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 65b0e463b61df80989037373e97d7623eb55d42f..d904bee3de4a9649efb14fe504fa811d729f9f5c 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) {