Reland 4e4eae4cbe6136b538a: Make download item drags look like bookmark

ui/views/drag_utils.cc

Index: ui/views/drag_utils.cc
diff --git a/ui/views/drag_utils.cc b/ui/views/drag_utils.cc
index 9c7251fc91f23495045ed748d95b24e29b3d0c1a..3a85cc8eb92851e60d8ebcbcb68a5b6a7077cdd0 100644
--- a/ui/views/drag_utils.cc
+++ b/ui/views/drag_utils.cc
@@ -11,7 +11,7 @@
 
 namespace views {
 
-float ScaleFactorForDragFromWidget(Widget* widget) {
+float ScaleFactorForDragFromWidget(const Widget* widget) {
   float device_scale = 1.0f;
   if (widget && widget->GetNativeView()) {
     gfx::NativeView view = widget->GetNativeView();
@@ -20,7 +20,7 @@ float ScaleFactorForDragFromWidget(Widget* widget) {
   return device_scale;
 }
 
-gfx::Canvas* GetCanvasForDragImage(Widget* widget,
+gfx::Canvas* GetCanvasForDragImage(const Widget* widget,
                                    const gfx::Size& canvas_size) {
   float device_scale = ScaleFactorForDragFromWidget(widget);
   return new gfx::Canvas(canvas_size, device_scale, false);