Move DropTargetEvent back to ui/base for the time being as it depends on OSExchangeData which I don…

ui/base/dragdrop/drop_target_event.cc

+// Copyright (c) 2013 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/base/dragdrop/drop_target_event.h"
+
+#include "ui/events/event_utils.h"
+
+namespace ui {
+
+////////////////////////////////////////////////////////////////////////////////
+// DropTargetEvent
+
+DropTargetEvent::DropTargetEvent(const OSExchangeData& data,
+                                 const gfx::Point& location,
+                                 const gfx::Point& root_location,
+                                 int source_operations)
+    : LocatedEvent(ET_DROP_TARGET_EVENT,
+                   location,
+                   root_location,
+                   EventTimeForNow(),
+                   0),
+      data_(data),
+      source_operations_(source_operations) {
+}
+
+}  // namespace ui
+