Do not handle the button click event for the mouse release of dragging launcher item.

ash/launcher/launcher_view.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 "ash/launcher/launcher_view.h"
 
 #include "ash/launcher/launcher_button.h"
 #include "ash/launcher/launcher_delegate.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/launcher/launcher_window_cycler.h"
@@ skipping 676 matching lines @@
       return l10n_util::GetStringUTF16(IDS_AURA_APP_LIST_TITLE);
 
     case TYPE_BROWSER_SHORTCUT:
       return l10n_util::GetStringUTF16(IDS_AURA_CYCLER_TITLE);
   }
   return string16();
 }
 
 void LauncherView::ButtonPressed(views::Button* sender,
                                  const views::Event& event) {
+  // Do not handle mouse release during drag.
+  if (dragging_)
+    return;
+
   if (sender == overflow_button_)
     ShowOverflowMenu();
 
   if (!delegate_)
     return;
   int view_index = view_model_->GetIndexOfView(sender);
   // May be -1 while in the process of animating closed.
   if (view_index == -1)
     return;
 
@@ skipping 37 matching lines @@
   // code.
   if (launcher_menu_runner_->RunMenuAt(
           source->GetWidget(), NULL, gfx::Rect(point, gfx::Size()),
           views::MenuItemView::TOPLEFT, 0) == views::MenuRunner::MENU_DELETED)
     return;
 #endif
 }
 
 }  // namespace internal
 }  // namespace ash