Simplify calls for scale factor

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.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 "ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <X11/Xatom.h>
 
 #include "base/event_types.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_macros.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/drag_drop_delegate.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/dragdrop/drop_target_event.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_aurax11.h"
+#include "ui/base/layout.h"
 #include "ui/base/x/selection_utils.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/base/x/x11_window_event_manager.h"
 #include "ui/display/screen.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/widget/desktop_aura/desktop_native_cursor_manager.h"
@@ skipping 849 matching lines @@
 void DesktopDragDropClientAuraX11::OnWindowDestroyed(aura::Window* window) {
   DCHECK_EQ(target_window_, window);
   target_window_ = NULL;
 }
 
 void DesktopDragDropClientAuraX11::OnMouseMovement(
     const gfx::Point& screen_point,
     int flags,
     base::TimeTicks event_time) {
   if (drag_widget_.get()) {
-    display::Display display =
-        display::Screen::GetScreen()->GetDisplayNearestWindow(
-            drag_widget_->GetNativeWindow());
-    gfx::Point scaled_point = gfx::ScaleToRoundedPoint(
-        screen_point, 1.f / display.device_scale_factor());
+    float scale_factor =
+        ui::GetScaleFactorForNativeView(drag_widget_->GetNativeWindow());
+    gfx::Point scaled_point =
+        gfx::ScaleToRoundedPoint(screen_point, 1.f / scale_factor);
     drag_widget_->SetBounds(
         gfx::Rect(scaled_point - drag_widget_offset_, drag_image_size_));
     drag_widget_->StackAtTop();
   }
 
   const int kModifiers = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
                          ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN |
                          ui::EF_LEFT_MOUSE_BUTTON |
                          ui::EF_MIDDLE_MOUSE_BUTTON |
                          ui::EF_RIGHT_MOUSE_BUTTON;
@@ skipping 448 matching lines @@
     for (int x = 0; x < in_bitmap->width(); ++x) {
       if (SkColorGetA(in_row[x]) > kMinAlpha)
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace views