Enable touch-initiated drag-drop work on Windows

ui/base/dragdrop/drag_source_win.cc

Index: ui/base/dragdrop/drag_source_win.cc
diff --git a/ui/base/dragdrop/drag_source_win.cc b/ui/base/dragdrop/drag_source_win.cc
index 90ce68273a3379b463e1d9571d9fc73dbd26ad3f..376922a4bc2a90c78e169d40d29a2a77fd7ea71a 100644
--- a/ui/base/dragdrop/drag_source_win.cc
+++ b/ui/base/dragdrop/drag_source_win.cc
@@ -18,7 +18,7 @@ HRESULT DragSourceWin::QueryContinueDrag(BOOL escape_pressed, DWORD key_state) {
     return DRAGDROP_S_CANCEL;
   }
 
-  if (!(key_state & MK_LBUTTON)) {
+  if (ShouldDropDragSource(escape_pressed, key_state)) {
     OnDragSourceDrop();
     return DRAGDROP_S_DROP;
   }
@@ -52,4 +52,9 @@ ULONG DragSourceWin::Release() {
   return 0;
 }
 
+bool DragSourceWin::ShouldDropDragSource(
+    BOOL escape_pressed,DWORD key_state) {
+  return !(key_state & MK_LBUTTON);
+}
+
 }  // namespace ui