Delete ash-based code for Windows drag-and-drop graphics.

ui/base/dragdrop/os_exchange_data_provider_aura.cc

Index: ui/base/dragdrop/os_exchange_data_provider_aura.cc
diff --git a/ui/base/dragdrop/os_exchange_data_provider_aura.cc b/ui/base/dragdrop/os_exchange_data_provider_aura.cc
index 6093a8e4f68a014e057080e3504dfe2c86eed6b6..200d0c88ce321fe3bbe1c58b318550bbe9a5a5f6 100644
--- a/ui/base/dragdrop/os_exchange_data_provider_aura.cc
+++ b/ui/base/dragdrop/os_exchange_data_provider_aura.cc
@@ -183,12 +183,11 @@ void OSExchangeDataProviderAura::SetDragImage(
   drag_image_offset_ = cursor_offset;
 }
 
-const gfx::ImageSkia& OSExchangeDataProviderAura::GetDragImage() const {
+gfx::ImageSkia OSExchangeDataProviderAura::GetDragImage() const {
   return drag_image_;
 }
 
-const gfx::Vector2d&
-OSExchangeDataProviderAura::GetDragImageOffset() const {
+gfx::Vector2d OSExchangeDataProviderAura::GetDragImageOffset() const {
   return drag_image_offset_;
 }