Makes Screen functions take a const gfx::NativeView

ui/display/test/test_screen.cc

Index: ui/display/test/test_screen.cc
diff --git a/ui/display/test/test_screen.cc b/ui/display/test/test_screen.cc
index cd96e35b85c7dcd57f2049185d344c58b48b6725..29b65daf01da1677a3023b52721f110a321cb412 100644
--- a/ui/display/test/test_screen.cc
+++ b/ui/display/test/test_screen.cc
@@ -35,7 +35,7 @@ std::vector<Display> TestScreen::GetAllDisplays() const {
   return std::vector<Display>(1, display_);
 }
 
-Display TestScreen::GetDisplayNearestWindow(gfx::NativeView view) const {
+Display TestScreen::GetDisplayNearestWindow(const gfx::NativeView view) const {
   return display_;
 }