GTK: Even more cleanup to access allocation through the accessor.

chrome/browser/ui/gtk/tabs/tab_gtk.cc

 // Copyright (c) 2011 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/ui/gtk/tabs/tab_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
@@ skipping 139 matching lines @@
       delegate_->ActivateTab(this);
     }
     observer_.reset();
 
     if (last_mouse_down_) {
       gdk_event_free(last_mouse_down_);
       last_mouse_down_ = NULL;
     }
   }
 
+  GtkAllocation allocation;
+  gtk_widget_get_allocation(widget, &allocation);
+
   // Middle mouse up means close the tab, but only if the mouse is over it
   // (like a button).
   if (event->button == 2 &&
       event->x >= 0 && event->y >= 0 &&
-      event->x < widget->allocation.width &&
-      event->y < widget->allocation.height) {
+      event->x < allocation.width &&
+      event->y < allocation.height) {
     // If the user is currently holding the left mouse button down but hasn't
     // moved the mouse yet, a drag hasn't started yet.  In that case, clean up
     // some state before closing the tab to avoid a crash.  Once the drag has
     // started, we don't get the middle mouse click here.
     if (last_mouse_down_) {
       DCHECK(!drag_widget_);
       observer_.reset();
       gdk_event_free(last_mouse_down_);
       last_mouse_down_ = NULL;
     }
@@ skipping 172 matching lines @@
     gdk_event_free(last_mouse_down_);
     last_mouse_down_ = NULL;
   }
 
   // Notify the drag helper that we're done with any potential drag operations.
   // Clean up the drag helper, which is re-created on the next mouse press.
   delegate_->EndDrag(canceled);
 
   observer_.reset();
 }