Fixes regression (and crash) in instant. The crash would happen if

views/focus/focus_manager.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 "views/focus/focus_manager.h"
 
 #include <algorithm>
 
 #include "build/build_config.h"
 
 #if defined(OS_LINUX)
 #include <gtk/gtk.h>
 #endif
 
+#include "base/auto_reset.h"
 #include "base/logging.h"
 #include "ui/base/keycodes/keyboard_codes.h"
 #include "views/accelerator.h"
 #include "views/focus/focus_search.h"
 #include "views/focus/view_storage.h"
 #include "views/view.h"
 #include "views/widget/root_view.h"
 #include "views/widget/widget.h"
 
 namespace views {
@@ skipping 29 matching lines @@
 FocusManager::WidgetFocusManager*
 FocusManager::WidgetFocusManager::GetInstance() {
   return Singleton<WidgetFocusManager>::get();
 }
 
 // FocusManager -----------------------------------------------------
 
 FocusManager::FocusManager(Widget* widget)
     : widget_(widget),
       focused_view_(NULL),
-      focus_change_reason_(kReasonDirectFocusChange) {
+      focus_change_reason_(kReasonDirectFocusChange),
+      is_changing_focus_(false) {
   DCHECK(widget_);
   stored_focused_view_storage_id_ =
       ViewStorage::GetInstance()->CreateStorageID();
 }
 
 FocusManager::~FocusManager() {
 }
 
 // static
 FocusManager::WidgetFocusManager* FocusManager::GetWidgetFocusManager() {
@@ skipping 188 matching lines @@
     }
   }
   return NULL;
 }
 
 void FocusManager::SetFocusedViewWithReason(
     View* view, FocusChangeReason reason) {
   if (focused_view_ == view)
     return;
 
+  AutoReset<bool> auto_changing_focus(&is_changing_focus_, true);
   // Update the reason for the focus change (since this is checked by
   // some listeners), then notify all listeners.
   focus_change_reason_ = reason;
   FOR_EACH_OBSERVER(FocusChangeListener, focus_change_listeners_,
                     FocusWillChange(focused_view_, view));
 
   if (focused_view_)
     focused_view_->Blur();
   focused_view_ = view;
   if (focused_view_)
@@ skipping 191 matching lines @@
 
 void FocusManager::AddFocusChangeListener(FocusChangeListener* listener) {
   focus_change_listeners_.AddObserver(listener);
 }
 
 void FocusManager::RemoveFocusChangeListener(FocusChangeListener* listener) {
   focus_change_listeners_.RemoveObserver(listener);
 }
 
 }  // namespace views