Move DisplayUtils methods into gfx::Screen.

ui/gfx/screen.h

Index: ui/gfx/screen.h
diff --git a/ui/gfx/screen.h b/ui/gfx/screen.h
index 0c712d47ea2bd1879536673b696f6656ecc03372..45a15adf3cb4e78e6acefd7593377de16d031377 100644
--- a/ui/gfx/screen.h
+++ b/ui/gfx/screen.h
@@ -9,6 +9,7 @@
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
+#include "ui/gfx/size.h"
 
 namespace gfx {
 
@@ -26,6 +27,7 @@ class UI_EXPORT Screen {
   static void SetInstance(Screen* screen);
 #endif
 
+  // Returns the current absolute position of the mouse pointer.
   static gfx::Point GetCursorScreenPoint();
 
   // Returns the work area of the monitor nearest the specified window.
@@ -44,6 +46,14 @@ class UI_EXPORT Screen {
   // Returns the window under the cursor.
   static gfx::NativeWindow GetWindowAtCursorScreenPoint();
 
+  // Returns the dimensions of the primary monitor in pixels.
+  static gfx::Size GetPrimaryMonitorSize();
+
+  // Returns the number of monitors.
+  // Mirrored displays are excluded; this method is intended to return the
+  // number of distinct, usable displays.
+  static int GetNumMonitors();
+
  protected:
   virtual gfx::Point GetCursorScreenPointImpl() = 0;
   virtual gfx::Rect GetMonitorWorkAreaNearestWindowImpl(
@@ -54,6 +64,8 @@ class UI_EXPORT Screen {
       const gfx::Point& point) = 0;
   virtual gfx::Rect GetMonitorAreaNearestPointImpl(const gfx::Point& point) = 0;
   virtual gfx::NativeWindow GetWindowAtCursorScreenPointImpl() = 0;
+  virtual gfx::Size GetPrimaryMonitorSizeImpl() = 0;
+  virtual int GetNumMonitorsImpl() = 0;
 
 private:
 #if defined(USE_AURA)