Make GetRootWindow() return a Window instead of a RootWindow.

ash/wm/partial_screenshot_view.cc

 // Copyright (c) 2012 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 "ash/wm/partial_screenshot_view.h"
 
 #include <algorithm>
 
 #include "ash/display/mouse_cursor_event_filter.h"
 #include "ash/screenshot_delegate.h"
@@ skipping 145 matching lines @@
   is_dragging_ = true;
 }
 
 void PartialScreenshotView::OnSelectionFinished() {
   overlay_delegate_->Cancel();
   if (!is_dragging_)
     return;
 
   is_dragging_ = false;
   if (screenshot_delegate_) {
-    aura::RootWindow *root_window =
+    aura::Window*root_window =
         GetWidget()->GetNativeWindow()->GetRootWindow();
     screenshot_delegate_->HandleTakePartialScreenshot(
         root_window,
         gfx::IntersectRects(root_window->bounds(), GetScreenshotRect()));
   }
 }
 
 gfx::NativeCursor PartialScreenshotView::GetCursor(
     const ui::MouseEvent& event) {
   // Always use "crosshair" cursor.
@@ skipping 57 matching lines @@
       OnSelectionFinished();
       break;
     default:
       break;
   }
 
   event->SetHandled();
 }
 
 }  // namespace ash