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

ash/extended_desktop_unittest.cc

Index: ash/extended_desktop_unittest.cc
diff --git a/ash/extended_desktop_unittest.cc b/ash/extended_desktop_unittest.cc
index 4cc75faa136612d24197472f18dd7330e5bfaf19..22182d3cf70629200a91046d32f06c4b46347d84 100644
--- a/ash/extended_desktop_unittest.cc
+++ b/ash/extended_desktop_unittest.cc
@@ -194,15 +194,18 @@ TEST_F(ExtendedDesktopTest, TestCursorLocation) {
   aura::Window::TestApi root_window1_test_api(root_windows[1]);
 
   root_windows[0]->MoveCursorTo(gfx::Point(10, 10));
-  EXPECT_EQ("10,10", gfx::Screen::GetCursorScreenPoint().ToString());
+  EXPECT_EQ("10,10",
+            Shell::GetAshScreen()->GetCursorScreenPoint().ToString());
   EXPECT_TRUE(root_window0_test_api.ContainsMouse());
   EXPECT_FALSE(root_window1_test_api.ContainsMouse());
   root_windows[1]->MoveCursorTo(gfx::Point(10, 20));
-  EXPECT_EQ("1010,20", gfx::Screen::GetCursorScreenPoint().ToString());
+  EXPECT_EQ("1010,20",
+            Shell::GetAshScreen()->GetCursorScreenPoint().ToString());
   EXPECT_FALSE(root_window0_test_api.ContainsMouse());
   EXPECT_TRUE(root_window1_test_api.ContainsMouse());
   root_windows[0]->MoveCursorTo(gfx::Point(20, 10));
-  EXPECT_EQ("20,10", gfx::Screen::GetCursorScreenPoint().ToString());
+  EXPECT_EQ("20,10",
+            Shell::GetAshScreen()->GetCursorScreenPoint().ToString());
   EXPECT_TRUE(root_window0_test_api.ContainsMouse());
   EXPECT_FALSE(root_window1_test_api.ContainsMouse());
 }
@@ -412,10 +415,10 @@ TEST_F(ExtendedDesktopTest, MoveWindowToDisplay) {
   UpdateDisplay("1000x1000,1000x1000");
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
 
-  gfx::Display display0 =
-      gfx::Screen::GetDisplayMatching(root_windows[0]->GetBoundsInScreen());
-  gfx::Display display1 =
-      gfx::Screen::GetDisplayMatching(root_windows[1]->GetBoundsInScreen());
+  gfx::Display display0 = Shell::GetAshScreen()->GetDisplayMatching(
+      root_windows[0]->GetBoundsInScreen());
+  gfx::Display display1 = Shell::GetAshScreen()->GetDisplayMatching(
+      root_windows[1]->GetBoundsInScreen());
   EXPECT_NE(display0.id(), display1.id());
 
   views::Widget* d1 = CreateTestWidget(gfx::Rect(10, 10, 1000, 100));