GTK: add more syncronization to GtkNativeViewIdManager to avoid a crash.

gfx/gtk_native_view_id_manager.cc

 // Copyright (c) 2009 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 "gfx/gtk_native_view_id_manager.h"
 
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "gfx/rect.h"
 
@@ skipping 98 matching lines @@
   std::map<gfx::NativeViewId, NativeViewInfo>::iterator i =
     id_to_info_.find(id);
 
   CHECK(i != id_to_info_.end());
   CHECK(widget->window);
 
   i->second.x_window_id = GDK_WINDOW_XID(widget->window);
 }
 
 void GtkNativeViewManager::OnUnrealize(gfx::NativeView widget) {
+  AutoLock unrealize_locked(unrealize_lock_);
   AutoLock locked(lock_);
 
   const gfx::NativeViewId id = GetWidgetId(widget);
   std::map<gfx::NativeViewId, NativeViewInfo>::iterator i =
     id_to_info_.find(id);
 
   CHECK(i != id_to_info_.end());
 
   i->second.x_window_id = 0;
 }
 
 void GtkNativeViewManager::OnDestroy(gfx::NativeView widget) {
   AutoLock locked(lock_);
 
   std::map<gfx::NativeView, gfx::NativeViewId>::iterator i =
     native_view_to_id_.find(widget);
   CHECK(i != native_view_to_id_.end());
 
   std::map<gfx::NativeViewId, NativeViewInfo>::iterator j =
     id_to_info_.find(i->second);
   CHECK(j != id_to_info_.end());
 
   native_view_to_id_.erase(i);
   id_to_info_.erase(j);
 }
 
 // -----------------------------------------------------------------------------