Send the device scale factor from Windows 8 ASH during initialization via the MetroViewerHostMsg_Se…

ui/aura/remote_window_tree_host_win.cc

Index: ui/aura/remote_window_tree_host_win.cc
diff --git a/ui/aura/remote_window_tree_host_win.cc b/ui/aura/remote_window_tree_host_win.cc
index 70412d33546cb81bf87b47e25d8fb223fe4d2c3a..b1f87a91fce3ac575124f18af36ca90a7b98a785 100644
--- a/ui/aura/remote_window_tree_host_win.cc
+++ b/ui/aura/remote_window_tree_host_win.cc
@@ -183,8 +183,11 @@ bool RemoteWindowTreeHostWin::IsValid() {
   return Instance()->remote_window_ != NULL;
 }
 
-void RemoteWindowTreeHostWin::SetRemoteWindowHandle(HWND remote_window) {
+void RemoteWindowTreeHostWin::InitializeRemoteWindowAndScaleFactor(
+    HWND remote_window,
+    float device_scale) {
   remote_window_ = remote_window;
+  gfx::InitDeviceScaleFactor(device_scale);
   // Do not create compositor here, but in Connected() below.
   // See http://crbug.com/330179 and http://crbug.com/334380.
 }