revert r53268:

chrome/browser/gtk/tabs/tab_strip_gtk.cc

 // Copyright (c) 2010 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 "chrome/browser/gtk/tabs/tab_strip_gtk.h"
 
 #include <algorithm>
 
 #include "app/gtk_dnd_util.h"
 #include "app/resource_bundle.h"
@@ skipping 754 matching lines @@
 }
 
 void TabStripGtk::Show() {
   gtk_widget_show(tabstrip_.get());
 }
 
 void TabStripGtk::Hide() {
   gtk_widget_hide(tabstrip_.get());
 }
 
-void TabStripGtk::CancelActiveDragSession() {
-  if (!IsDragSessionActive())
-   return;
-
-  drag_controller_->EndDrag(true);
-}
-
 void TabStripGtk::Layout() {
   // Called from:
   // - window resize
   // - animation completion
   StopAnimation();
 
   GenerateIdealBounds();
   int tab_count = GetTabCount();
   int tab_right = 0;
   for (int i = 0; i < tab_count; ++i) {
@@ skipping 1248 matching lines @@
 
   // Let the middle mouse button initiate clicks as well.
   gtk_util::SetButtonTriggersNavigation(button->widget());
   g_signal_connect(button->widget(), "clicked",
                    G_CALLBACK(OnNewTabClickedThunk), this);
   GTK_WIDGET_UNSET_FLAGS(button->widget(), GTK_CAN_FOCUS);
   gtk_fixed_put(GTK_FIXED(tabstrip_.get()), button->widget(), 0, 0);
 
   return button;
 }