Revert of Move base/prefs to components/prefs

base/prefs/pref_change_registrar.cc

Index: base/prefs/pref_change_registrar.cc
diff --git a/base/prefs/pref_change_registrar.cc b/base/prefs/pref_change_registrar.cc
new file mode 100644
index 0000000000000000000000000000000000000000..13193484ff449c348be51f94d35474968ae7efe7
--- /dev/null
+++ b/base/prefs/pref_change_registrar.cc
@@ -0,0 +1,94 @@
+// 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 "base/prefs/pref_change_registrar.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/prefs/pref_service.h"
+
+PrefChangeRegistrar::PrefChangeRegistrar() : service_(NULL) {}
+
+PrefChangeRegistrar::~PrefChangeRegistrar() {
+  // If you see an invalid memory access in this destructor, this
+  // PrefChangeRegistrar might be subscribed to an OffTheRecordProfileImpl that
+  // has been destroyed. This should not happen any more but be warned.
+  // Feel free to contact battre@chromium.org in case this happens.
+  RemoveAll();
+}
+
+void PrefChangeRegistrar::Init(PrefService* service) {
+  DCHECK(IsEmpty() || service_ == service);
+  service_ = service;
+}
+
+void PrefChangeRegistrar::Add(const std::string& path,
+                              const base::Closure& obs) {
+  Add(path, base::Bind(&PrefChangeRegistrar::InvokeUnnamedCallback, obs));
+}
+
+void PrefChangeRegistrar::Add(const std::string& path,
+                              const NamedChangeCallback& obs) {
+  if (!service_) {
+    NOTREACHED();
+    return;
+  }
+  DCHECK(!IsObserved(path)) << "Already had this pref registered.";
+
+  service_->AddPrefObserver(path, this);
+  observers_[path] = obs;
+}
+
+void PrefChangeRegistrar::Remove(const std::string& path) {
+  DCHECK(IsObserved(path));
+
+  observers_.erase(path);
+  service_->RemovePrefObserver(path, this);
+}
+
+void PrefChangeRegistrar::RemoveAll() {
+  for (ObserverMap::const_iterator it = observers_.begin();
+       it != observers_.end(); ++it) {
+    service_->RemovePrefObserver(it->first, this);
+  }
+
+  observers_.clear();
+}
+
+bool PrefChangeRegistrar::IsEmpty() const {
+  return observers_.empty();
+}
+
+bool PrefChangeRegistrar::IsObserved(const std::string& pref) {
+  return observers_.find(pref) != observers_.end();
+}
+
+bool PrefChangeRegistrar::IsManaged() {
+  for (ObserverMap::const_iterator it = observers_.begin();
+       it != observers_.end(); ++it) {
+    const PrefService::Preference* pref = service_->FindPreference(it->first);
+    if (pref && pref->IsManaged())
+      return true;
+  }
+  return false;
+}
+
+void PrefChangeRegistrar::OnPreferenceChanged(PrefService* service,
+                                              const std::string& pref) {
+  if (IsObserved(pref))
+    observers_[pref].Run(pref);
+}
+
+void PrefChangeRegistrar::InvokeUnnamedCallback(const base::Closure& callback,
+                                                const std::string& pref_name) {
+  callback.Run();
+}
+
+PrefService* PrefChangeRegistrar::prefs() {
+  return service_;
+}
+
+const PrefService* PrefChangeRegistrar::prefs() const {
+  return service_;
+}