Adding UMA stats for dragdrop events for both touch and mouse.

ui/views/widget/desktop_aura/desktop_drag_drop_client_win.cc

 // Copyright (c) 2012 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/views/widget/desktop_aura/desktop_drag_drop_client_win.h"
 
+#include "base/metrics/histogram_macros.h"
 #include "base/tracked_objects.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/drag_source_win.h"
 #include "ui/base/dragdrop/drop_target_event.h"
 #include "ui/base/dragdrop/os_exchange_data_provider_win.h"
 #include "ui/views/widget/desktop_aura/desktop_drop_target_win.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host_win.h"
 
 namespace views {
 
@@ skipping 21 matching lines @@
   drag_drop_in_progress_ = true;
   drag_operation_ = operation;
 
   base::WeakPtr<DesktopDragDropClientWin> alive(weak_factory_.GetWeakPtr());
 
   drag_source_ = new ui::DragSourceWin;
   scoped_refptr<ui::DragSourceWin> drag_source_copy = drag_source_;
 
   DWORD effect;
 
+  UMA_HISTOGRAM_ENUMERATION("Event.DragDrop.Start", source,
+                            ui::DragDropTypes::DRAG_EVENT_SOURCE_COUNT);
+
   // Use task stopwatch to exclude the drag-drop time current task, if any.
   tracked_objects::TaskStopwatch stopwatch;
   stopwatch.Start();
   HRESULT result = DoDragDrop(
       ui::OSExchangeDataProviderWin::GetIDataObject(data), drag_source_.get(),
       ui::DragDropTypes::DragOperationToDropEffect(operation), &effect);
   stopwatch.Stop();
 
   if (alive)
     drag_drop_in_progress_ = false;
 
   if (result != DRAGDROP_S_DROP)
     effect = DROPEFFECT_NONE;
 
-  return ui::DragDropTypes::DropEffectToDragOperation(effect);
+  int drag_operation = ui::DragDropTypes::DropEffectToDragOperation(effect);
+
+  if (drag_operation == ui::DragDropTypes::DRAG_NONE) {
+    UMA_HISTOGRAM_ENUMERATION("Event.DragDrop.Cancel", source,
+                              ui::DragDropTypes::DRAG_EVENT_SOURCE_COUNT);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Event.DragDrop.Drop", source,
+                              ui::DragDropTypes::DRAG_EVENT_SOURCE_COUNT);
+  }
+
+  return drag_operation;
 }
 
 void DesktopDragDropClientWin::DragUpdate(aura::Window* target,
                                           const ui::LocatedEvent& event) {
 }
 
 void DesktopDragDropClientWin::Drop(aura::Window* target,
                                     const ui::LocatedEvent& event) {
 }
 
 void DesktopDragDropClientWin::DragCancel() {
   drag_source_->CancelDrag();
   drag_operation_ = 0;
 }
 
 bool DesktopDragDropClientWin::IsDragDropInProgress() {
   return drag_drop_in_progress_;
 }
 
 void DesktopDragDropClientWin::OnNativeWidgetDestroying(HWND window) {
   if (drop_target_.get()) {
     RevokeDragDrop(window);
     drop_target_ = NULL;
   }
 }
 
 }  // namespace views