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

ui/gfx/screen_ios.mm

Index: ui/gfx/screen_ios.mm
diff --git a/ui/gfx/screen_ios.mm b/ui/gfx/screen_ios.mm
index 42b2edd5ec141b0fa5232aa6438b1e8a01042362..c23ff745533f629bbfca52e626b486b7afe5129f 100644
--- a/ui/gfx/screen_ios.mm
+++ b/ui/gfx/screen_ios.mm
@@ -11,14 +11,14 @@
 namespace gfx {
 
 // static
-gfx::Display Screen::GetPrimaryDisplay() {
+gfx::Display Screen::GetPrimaryDisplay(gfx::NativeView context) {
   UIScreen* mainScreen = [[UIScreen screens] objectAtIndex:0];
   gfx::Display display(0, gfx::Rect(mainScreen.bounds));
   return display;
 }
 
 // static
-int Screen::GetNumDisplays() {
+int Screen::GetNumDisplays(gfx::NativeView context) {
 #if TARGET_IPHONE_SIMULATOR
   // UIScreen does not reliably return correct results on the simulator.
   return 1;