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

ash/wm/shelf_layout_manager_unittest.cc

Index: ash/wm/shelf_layout_manager_unittest.cc
diff --git a/ash/wm/shelf_layout_manager_unittest.cc b/ash/wm/shelf_layout_manager_unittest.cc
index 4428c5d548973b09668fe80be503a71f87265b61..883e622b5b390e72b8c44245513d421d2d6f3942 100644
--- a/ash/wm/shelf_layout_manager_unittest.cc
+++ b/ash/wm/shelf_layout_manager_unittest.cc
@@ -218,9 +218,11 @@ TEST_F(ShelfLayoutManagerTest, MAYBE_SetVisible) {
 
   // Make sure the bounds of the two widgets changed.
   EXPECT_GE(shelf->launcher_widget()->GetNativeView()->bounds().y(),
-            gfx::Screen::GetPrimaryDisplay().bounds().bottom());
+            gfx::Screen::GetPrimaryDisplay(
+                ash::Shell::GetRootNativeView()).bounds().bottom());
   EXPECT_GE(shelf->status()->GetNativeView()->bounds().y(),
-            gfx::Screen::GetPrimaryDisplay().bounds().bottom());
+            gfx::Screen::GetPrimaryDisplay(
+                ash::Shell::GetRootNativeView()).bounds().bottom());
 
   // And show it again.
   SetState(shelf, ShelfLayoutManager::VISIBLE);
@@ -233,8 +235,8 @@ TEST_F(ShelfLayoutManagerTest, MAYBE_SetVisible) {
 
   // Make sure the bounds of the two widgets changed.
   launcher_bounds = shelf->launcher_widget()->GetNativeView()->bounds();
-  int bottom = gfx::Screen::GetPrimaryDisplay().bounds().bottom() -
-      shelf_height;
+  int bottom = gfx::Screen::GetPrimaryDisplay(
+        ash::Shell::GetRootNativeView()).bounds().bottom() - shelf_height;
   EXPECT_EQ(launcher_bounds.y(),
             bottom + (shelf->GetIdealBounds().height() -
                       launcher_bounds.height()) / 2);
@@ -263,9 +265,11 @@ TEST_F(ShelfLayoutManagerTest, LayoutShelfWhileAnimating) {
 
   // Make sure the bounds of the two widgets changed.
   EXPECT_GE(shelf->launcher_widget()->GetNativeView()->bounds().y(),
-            gfx::Screen::GetPrimaryDisplay().bounds().bottom());
+            gfx::Screen::GetPrimaryDisplay(
+                ash::Shell::GetRootNativeView()).bounds().bottom());
   EXPECT_GE(shelf->status()->GetNativeView()->bounds().y(),
-            gfx::Screen::GetPrimaryDisplay().bounds().bottom());
+            gfx::Screen::GetPrimaryDisplay(
+                ash::Shell::GetRootNativeView()).bounds().bottom());
 }
 
 // Makes sure the launcher is initially sized correctly.