Disable touch calibration on external touchscreen.

ui/aura/root_window.cc

Index: ui/aura/root_window.cc
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index 96cb84a9f1d5178c9357881a22eb2a55553a59bc..a23996272ab796f3c74a7190b6a267de96bb3df2 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -84,15 +84,18 @@ void SetLastMouseLocation(const RootWindow* root_window,
 RootWindowHost* CreateHost(RootWindow* root_window,
                            const RootWindow::CreateParams& params) {
   RootWindowHost* host = params.host ?
-      params.host : RootWindowHost::Create(params.initial_bounds);
+      params.host : RootWindowHost::Create(params.initial_bounds,
+                                           params.is_internal_display);
   host->SetDelegate(root_window);
   return host;
 }
 
 }  // namespace
 
-RootWindow::CreateParams::CreateParams(const gfx::Rect& a_initial_bounds)
+RootWindow::CreateParams::CreateParams(const gfx::Rect& a_initial_bounds,
+                                       bool a_is_internal_display)
     : initial_bounds(a_initial_bounds),
+      is_internal_display(a_is_internal_display),
       host(NULL) {
 }