Add context to gfx::Screen calls in support of simultaneous desktop+ash

ash/display/display_controller.cc

Index: ash/display/display_controller.cc
diff --git a/ash/display/display_controller.cc b/ash/display/display_controller.cc
index b7361c375631f5872f888d4edf2034aad5febb37..dccc2263981c8fc0d489c9e75982714df84de96f 100644
--- a/ash/display/display_controller.cc
+++ b/ash/display/display_controller.cc
@@ -469,10 +469,10 @@ aura::RootWindow* DisplayController::AddRootWindowForDisplay(
 }
 
 void DisplayController::UpdateDisplayBoundsForLayout() {
-  if (gfx::Screen::GetNumDisplays() <= 1)
+  if (gfx::Screen::GetNumDisplays(ash::Shell::GetRootNativeView()) <= 1)

[Ben Goodger (Google), 2012/10/04 15:38:37]

is it acceptable to use the active root window in these cases? what did oshima
think of this?

     return;
 
-  DCHECK_EQ(2, gfx::Screen::GetNumDisplays());
+  DCHECK_EQ(2, gfx::Screen::GetNumDisplays(ash::Shell::GetRootNativeView()));
   const gfx::Rect& primary_bounds = GetPrimaryDisplay().bounds();
 
   gfx::Display* secondary_display = GetSecondaryDisplay();