Makes Screen functions take a const gfx::NativeView

ui/display/test/test_screen.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <vector>
 
 #include "ui/display/test/test_screen.h"
 
 namespace display {
 namespace test {
@@ skipping 17 matching lines @@
 }
 
 int TestScreen::GetNumDisplays() const {
   return 1;
 }
 
 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_;
 }
 
 Display TestScreen::GetDisplayNearestPoint(const gfx::Point& point) const {
   return display_;
 }
 
 Display TestScreen::GetDisplayMatching(const gfx::Rect& match_rect) const {
   return display_;
 }
 
 Display TestScreen::GetPrimaryDisplay() const {
   return display_;
 }
 
 void TestScreen::AddObserver(DisplayObserver* observer) {
 }
 
 void TestScreen::RemoveObserver(DisplayObserver* observer) {
 }
 
 }  // namespace test
 }  // namespace display