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

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
 
 #include <X11/Xlib.h>
+
 #include <set>
+#include <utility>

[mfomitchev, 2015/01/13 17:01:25]

Doesn't seem like this should be needed.

[caelyn, 2015/01/13 23:48:58]

Added because lint suggested it, removing it and all other new imports that are
not necessary for compilation.

 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/timer/timer.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/cursor/cursor.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 235 matching lines @@
   SourceState source_state_;
 
   // The current drag-drop client that has an active operation. Since we have
   // multiple root windows and multiple DesktopDragDropClientAuraX11 instances
   // it is important to maintain only one drag and drop operation at any time.
   static DesktopDragDropClientAuraX11* g_current_drag_drop_client;
 
   // The operation bitfield as requested by StartDragAndDrop.
   int drag_operation_;
 
+  // The DragEventSource as reported by StartDragAndDrop.
+  ui::DragDropTypes::DragEventSource current_drag_event_source_;
+
   // We offer the other window a list of possible operations,
   // XdndActionsList. This is the requested action from the other window. This
   // is DRAG_NONE if we haven't sent out an XdndPosition message yet, haven't
   // yet received an XdndStatus or if the other window has told us that there's
   // no action that we can agree on.
   ui::DragDropTypes::DragOperation negotiated_operation_;
 
   // Ends the move loop if the target is too slow to respond after the mouse is
   // released.
   base::OneShotTimer<DesktopDragDropClientAuraX11> end_move_loop_timer_;
 
   // Widget that the user drags around. May be NULL.
   scoped_ptr<Widget> drag_widget_;
 
   // The offset of |drag_widget_| relative to the mouse position.
   gfx::Vector2d drag_widget_offset_;
 
   base::WeakPtrFactory<DesktopDragDropClientAuraX11> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopDragDropClientAuraX11);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_