Move DisplayUtils methods into gfx::Screen.

ui/gfx/screen_aura.cc

Index: ui/gfx/screen_aura.cc
diff --git a/ui/gfx/screen_aura.cc b/ui/gfx/screen_aura.cc
index 097fe8cf20e6e303408719fc707c2d778c110f11..0093af6aceb26a423ad06302f4f8a557abae0741 100644
--- a/ui/gfx/screen_aura.cc
+++ b/ui/gfx/screen_aura.cc
@@ -24,38 +24,42 @@ void Screen::SetInstance(Screen* screen) {
 
 // static
 gfx::Point Screen::GetCursorScreenPoint() {
-  DCHECK(instance_);
   return instance_->GetCursorScreenPointImpl();
 }
 
 // static
 gfx::Rect Screen::GetMonitorWorkAreaNearestWindow(gfx::NativeWindow window) {
-  DCHECK(instance_);
   return instance_->GetMonitorWorkAreaNearestWindowImpl(window);
 }
 
 // static
 gfx::Rect Screen::GetMonitorAreaNearestWindow(gfx::NativeWindow window) {
-  DCHECK(instance_);
   return instance_->GetMonitorAreaNearestWindowImpl(window);
 }
 
 // static
 gfx::Rect Screen::GetMonitorWorkAreaNearestPoint(const gfx::Point& point) {
-  DCHECK(instance_);
   return instance_->GetMonitorWorkAreaNearestPointImpl(point);
 }
 
 // static
 gfx::Rect Screen::GetMonitorAreaNearestPoint(const gfx::Point& point) {
-  DCHECK(instance_);
   return instance_->GetMonitorAreaNearestPointImpl(point);
 }
 
 // static
 gfx::NativeWindow Screen::GetWindowAtCursorScreenPoint() {
-  DCHECK(instance_);
   return instance_->GetWindowAtCursorScreenPointImpl();
 }
 
+// static
+gfx::Size Screen::GetPrimaryMonitorSize() {
+  return instance_->GetPrimaryMonitorSizeImpl();
+}
+
+// static
+int Screen::GetNumMonitors() {
+  return instance_->GetNumMonitorsImpl();
+}
+
 }  // namespace gfx