mash: remove more shell/shelf WmWindow usage.

ash/drag_drop/drag_drop_tracker_unittest.cc

Index: ash/drag_drop/drag_drop_tracker_unittest.cc
diff --git a/ash/drag_drop/drag_drop_tracker_unittest.cc b/ash/drag_drop/drag_drop_tracker_unittest.cc
index 1090b5aa57c75ef825fd36bfd8492574767dc99a..b8c37965a6e67c0024648f05f0b54acbddcb7c54 100644
--- a/ash/drag_drop/drag_drop_tracker_unittest.cc
+++ b/ash/drag_drop/drag_drop_tracker_unittest.cc
@@ -66,8 +66,7 @@ TEST_F(DragDropTrackerTest, GetTarget) {
   EXPECT_EQ("300,100 100x100", window1->GetBoundsInScreen().ToString());
 
   // RootWindow0 is active so the capture window is parented to it.
-  EXPECT_EQ(WmWindow::Get(root_windows[0]),
-            Shell::GetWmRootWindowForNewWindows());
+  EXPECT_EQ(root_windows[0], Shell::GetRootWindowForNewWindows());
 
   // Start tracking from the RootWindow1 and check the point on RootWindow0 that
   // |window0| covers.
@@ -88,8 +87,7 @@ TEST_F(DragDropTrackerTest, GetTarget) {
   EXPECT_NE(window1.get(), GetTarget(gfx::Point(50, 250)));
 
   // Make RootWindow1 active so that capture window is parented to it.
-  ScopedRootWindowForNewWindows root_for_new_windows(
-      WmWindow::Get(root_windows[1]));
+  ScopedRootWindowForNewWindows root_for_new_windows(root_windows[1]);
 
   // Start tracking from the RootWindow1 and check the point on RootWindow0 that
   // |window0| covers.
@@ -124,8 +122,7 @@ TEST_F(DragDropTrackerTest, ConvertEvent) {
   window1->Show();
 
   // RootWindow0 is active so the capture window is parented to it.
-  EXPECT_EQ(WmWindow::Get(root_windows[0]),
-            Shell::GetWmRootWindowForNewWindows());
+  EXPECT_EQ(root_windows[0], Shell::GetRootWindowForNewWindows());
 
   // Start tracking from the RootWindow0 and converts the mouse event into
   // |window0|'s coodinates.
@@ -152,8 +149,7 @@ TEST_F(DragDropTrackerTest, ConvertEvent) {
   EXPECT_EQ(original01.flags(), converted01->flags());
 
   // Make RootWindow1 active so that capture window is parented to it.
-  ScopedRootWindowForNewWindows root_for_new_windows(
-      WmWindow::Get(root_windows[1]));
+  ScopedRootWindowForNewWindows root_for_new_windows(root_windows[1]);
 
   // Start tracking from the RootWindow1 and converts the mouse event into
   // |window0|'s coodinates.