Rename WindowTreeHost functions to indicate pixels/dips.

ash/host/ash_window_tree_host_platform.cc

Index: ash/host/ash_window_tree_host_platform.cc
diff --git a/ash/host/ash_window_tree_host_platform.cc b/ash/host/ash_window_tree_host_platform.cc
index 8f140ba9085475b8ad9daee4a5b40b92fdbdbcdb..eb08e74debd25f00509e819192aa0b57cff27e98 100644
--- a/ash/host/ash_window_tree_host_platform.cc
+++ b/ash/host/ash_window_tree_host_platform.cc
@@ -90,9 +90,9 @@ gfx::Transform AshWindowTreeHostPlatform::GetInverseRootTransform() const {
   return transformer_helper_.GetInverseTransform();
 }
 
-void AshWindowTreeHostPlatform::UpdateRootWindowSize(
-    const gfx::Size& host_size) {
-  transformer_helper_.UpdateWindowSize(host_size);
+void AshWindowTreeHostPlatform::UpdateRootWindowSizeInPixel(
+    const gfx::Size& host_size_in_pixel) {
+  transformer_helper_.UpdateWindowSize(host_size_in_pixel);
 }
 
 void AshWindowTreeHostPlatform::OnCursorVisibilityChangedNative(bool show) {