Make aura::clients take Window instead of RootWindow

ash/drag_drop/drag_drop_controller.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/drag_drop/drag_drop_controller.h"
 
 #include "ash/drag_drop/drag_drop_tracker.h"
 #include "ash/drag_drop/drag_image_view.h"
 #include "ash/shell.h"
 #include "ash/wm/coordinate_conversion.h"
@@ skipping 15 matching lines @@
 #include "ui/gfx/path.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/native_widget_aura.h"
 
 namespace ash {
 namespace internal {
 
-using aura::RootWindow;
-
 namespace {
 // The duration of the drag cancel animation in millisecond.
 const int kCancelAnimationDuration = 250;
 const int kTouchCancelAnimationDuration = 20;
 // The frame rate of the drag cancel animation in hertz.
 const int kCancelAnimationFrameRate = 60;
 
 // For touch initiated dragging, we scale and shift drag image by the following:
 static const float kTouchDragImageScale = 1.2f;
 static const int kTouchDragImageVerticalOffset = -25;
@@ skipping 105 matching lines @@
   Shell::GetInstance()->RemovePreTargetHandler(this);
   Cleanup();
   if (cancel_animation_)
     cancel_animation_->End();
   if (drag_image_)
     drag_image_.reset();
 }
 
 int DragDropController::StartDragAndDrop(
     const ui::OSExchangeData& data,
-    aura::RootWindow* root_window,
+    aura::Window* root_window,
     aura::Window* source_window,
     const gfx::Point& root_location,
     int operation,
     ui::DragDropTypes::DragEventSource source) {
   if (IsDragDropInProgress())
     return 0;
 
   const ui::OSExchangeData::Provider* provider = &data.provider();
   // We do not support touch drag/drop without a drag image.
   if (source == ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH &&
@@ skipping 389 matching lines @@
     drag_window_->RemoveObserver(this);
   drag_window_ = NULL;
   drag_data_ = NULL;
   // Cleanup can be called again while deleting DragDropTracker, so use Pass
   // instead of reset to avoid double free.
   drag_drop_tracker_.Pass();
 }
 
 }  // namespace internal
 }  // namespace ash