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

ash/launcher/launcher_button.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_button.h"
 
 #include <algorithm>
 
 #include "ash/launcher/launcher_button_host.h"
 #include "grit/ui_resources.h"
@@ skipping 138 matching lines @@
   return icon_view_->bounds();
 }
 
 bool LauncherButton::OnMousePressed(const views::MouseEvent& event) {
   CustomButton::OnMousePressed(event);
   host_->MousePressedOnButton(this, event);
   return true;
 }
 
 void LauncherButton::OnMouseReleased(const views::MouseEvent& event) {
+  CustomButton::OnMouseReleased(event);
   host_->MouseReleasedOnButton(this, false);
-  CustomButton::OnMouseReleased(event);
 }
 
 void LauncherButton::OnMouseCaptureLost() {
   ClearState(STATE_HOVERED);
   host_->MouseReleasedOnButton(this, true);
   CustomButton::OnMouseCaptureLost();
 }
 
 bool LauncherButton::OnMouseDragged(const views::MouseEvent& event) {
   CustomButton::OnMouseDragged(event);
@@ skipping 67 matching lines @@
       bar_id = IDR_AURA_LAUNCHER_UNDERLINE_RUNNING;
 
     bar_->SetImage(rb.GetImageNamed(bar_id).ToSkBitmap());
   }
 
   Layout();
   SchedulePaint();
 }
 }  // namespace internal
 }  // namespace ash