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

ui/base/BUILD.gn

Index: ui/base/BUILD.gn
diff --git a/ui/base/BUILD.gn b/ui/base/BUILD.gn
index 7fddc3bc1ace1336b844204ce5cd708d2e2c392f..7c32d81578033af1a369bd67adddc29697e2ff5c 100644
--- a/ui/base/BUILD.gn
+++ b/ui/base/BUILD.gn
@@ -165,7 +165,6 @@ component("base") {
     "dragdrop/drag_drop_types_win.cc",
     "dragdrop/drag_source_win.cc",
     "dragdrop/drag_source_win.h",
-    "dragdrop/drag_utils_win.cc",
     "dragdrop/drop_target_event.cc",
     "dragdrop/drop_target_event.h",
     "dragdrop/drop_target_win.cc",
@@ -339,8 +338,6 @@ component("base") {
       "default_theme_provider.h",
       "dragdrop/cocoa_dnd_util.h",
       "dragdrop/cocoa_dnd_util.mm",
-      "dragdrop/drag_utils.cc",
-      "dragdrop/drag_utils.h",
       "dragdrop/file_info.cc",
       "dragdrop/file_info.h",
       "idle/idle.cc",
@@ -488,15 +485,6 @@ component("base") {
     ]
   }
 
-  if (is_linux) {
-    if (!toolkit_views && !use_aura) {
-      sources -= [
-        "dragdrop/drag_utils.cc",
-        "dragdrop/drag_utils.h",
-      ]
-    }
-  }
-
   if (is_chromeos) {
     deps += [ "//chromeos" ]
     sources -= [ "idle/idle_linux.cc" ]
@@ -606,8 +594,6 @@ component("base") {
       "cursor/image_cursors.cc",
       "cursor/image_cursors.h",
       "default_theme_provider.cc",
-      "dragdrop/drag_utils.cc",
-      "dragdrop/drag_utils.h",
       "idle/idle.cc",
       "idle/idle.h",
       "idle/idle_android.cc",