Revert of Move base/prefs to components/prefs

base/prefs/pref_notifier_impl.cc

Index: base/prefs/pref_notifier_impl.cc
diff --git a/base/prefs/pref_notifier_impl.cc b/base/prefs/pref_notifier_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7ae5fe679f80e3e54e6cef34a1141c16419431af
--- /dev/null
+++ b/base/prefs/pref_notifier_impl.cc
@@ -0,0 +1,117 @@
+// 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 "base/prefs/pref_notifier_impl.h"
+
+#include "base/logging.h"
+#include "base/prefs/pref_service.h"
+#include "base/stl_util.h"
+
+PrefNotifierImpl::PrefNotifierImpl()
+    : pref_service_(NULL) {
+}
+
+PrefNotifierImpl::PrefNotifierImpl(PrefService* service)
+    : pref_service_(service) {
+}
+
+PrefNotifierImpl::~PrefNotifierImpl() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Verify that there are no pref observers when we shut down.
+  for (PrefObserverMap::iterator it = pref_observers_.begin();
+       it != pref_observers_.end(); ++it) {
+    PrefObserverList::Iterator obs_iterator(it->second);
+    if (obs_iterator.GetNext()) {
+      LOG(WARNING) << "pref observer found at shutdown " << it->first;
+    }
+  }
+
+  // Same for initialization observers.
+  if (!init_observers_.empty())
+    LOG(WARNING) << "Init observer found at shutdown.";
+
+  STLDeleteContainerPairSecondPointers(pref_observers_.begin(),
+                                       pref_observers_.end());
+  pref_observers_.clear();
+  init_observers_.clear();
+}
+
+void PrefNotifierImpl::AddPrefObserver(const std::string& path,
+                                       PrefObserver* obs) {
+  // Get the pref observer list associated with the path.
+  PrefObserverList* observer_list = NULL;
+  const PrefObserverMap::iterator observer_iterator =
+      pref_observers_.find(path);
+  if (observer_iterator == pref_observers_.end()) {
+    observer_list = new PrefObserverList;
+    pref_observers_[path] = observer_list;
+  } else {
+    observer_list = observer_iterator->second;
+  }
+
+  // Add the pref observer. ObserverList will DCHECK if it already is
+  // in the list.
+  observer_list->AddObserver(obs);
+}
+
+void PrefNotifierImpl::RemovePrefObserver(const std::string& path,
+                                          PrefObserver* obs) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const PrefObserverMap::iterator observer_iterator =
+      pref_observers_.find(path);
+  if (observer_iterator == pref_observers_.end()) {
+    return;
+  }
+
+  PrefObserverList* observer_list = observer_iterator->second;
+  observer_list->RemoveObserver(obs);
+}
+
+void PrefNotifierImpl::AddInitObserver(base::Callback<void(bool)> obs) {
+  init_observers_.push_back(obs);
+}
+
+void PrefNotifierImpl::OnPreferenceChanged(const std::string& path) {
+  FireObservers(path);
+}
+
+void PrefNotifierImpl::OnInitializationCompleted(bool succeeded) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // We must make a copy of init_observers_ and clear it before we run
+  // observers, or we can end up in this method re-entrantly before
+  // clearing the observers list.
+  PrefInitObserverList observers(init_observers_);
+  init_observers_.clear();
+
+  for (PrefInitObserverList::iterator it = observers.begin();
+       it != observers.end();
+       ++it) {
+    it->Run(succeeded);
+  }
+}
+
+void PrefNotifierImpl::FireObservers(const std::string& path) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Only send notifications for registered preferences.
+  if (!pref_service_->FindPreference(path))
+    return;
+
+  const PrefObserverMap::iterator observer_iterator =
+      pref_observers_.find(path);
+  if (observer_iterator == pref_observers_.end())
+    return;
+
+  FOR_EACH_OBSERVER(PrefObserver,
+                    *(observer_iterator->second),
+                    OnPreferenceChanged(pref_service_, path));
+}
+
+void PrefNotifierImpl::SetPrefService(PrefService* pref_service) {
+  DCHECK(pref_service_ == NULL);
+  pref_service_ = pref_service;
+}