Remove stl_util's STLDeleteContainerPairSecondPointers.

components/syncable_prefs/pref_model_associator.cc

Index: components/syncable_prefs/pref_model_associator.cc
diff --git a/components/syncable_prefs/pref_model_associator.cc b/components/syncable_prefs/pref_model_associator.cc
index c43679f3921b21729779aed0a94e9703223efd6c..a2758de670f2589dd33cf51e5a80d8df4074a4a4 100644
--- a/components/syncable_prefs/pref_model_associator.cc
+++ b/components/syncable_prefs/pref_model_associator.cc
@@ -12,7 +12,6 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
-#include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "components/prefs/pref_service.h"
@@ -70,8 +69,6 @@ PrefModelAssociator::~PrefModelAssociator() {
   DCHECK(CalledOnValidThread());
   pref_service_ = NULL;
 
-  base::STLDeleteContainerPairSecondPointers(synced_pref_observers_.begin(),
-                                             synced_pref_observers_.end());
   synced_pref_observers_.clear();
 }
 
@@ -442,21 +439,20 @@ bool PrefModelAssociator::IsPrefSynced(const std::string& name) const {
 
 void PrefModelAssociator::AddSyncedPrefObserver(const std::string& name,
     SyncedPrefObserver* observer) {
-  SyncedPrefObserverList* observers = synced_pref_observers_[name];
-  if (observers == NULL) {
-    observers = new SyncedPrefObserverList;
-    synced_pref_observers_[name] = observers;
-  }
+  std::unique_ptr<SyncedPrefObserverList>& observers =
+      synced_pref_observers_[name];
+  if (!observers)
+    observers = base::MakeUnique<SyncedPrefObserverList>();
+
   observers->AddObserver(observer);
 }
 
 void PrefModelAssociator::RemoveSyncedPrefObserver(const std::string& name,
     SyncedPrefObserver* observer) {
-  SyncedPrefObserverMap::iterator observer_iter =
-      synced_pref_observers_.find(name);
+  auto observer_iter = synced_pref_observers_.find(name);
   if (observer_iter == synced_pref_observers_.end())
     return;
-  SyncedPrefObserverList* observers = observer_iter->second;
+  SyncedPrefObserverList* observers = observer_iter->second.get();
   observers->RemoveObserver(observer);
 }
 
@@ -538,11 +534,10 @@ void PrefModelAssociator::SetPrefService(PrefServiceSyncable* pref_service) {
 
 void PrefModelAssociator::NotifySyncedPrefObservers(const std::string& path,
                                                     bool from_sync) const {
-  SyncedPrefObserverMap::const_iterator observer_iter =
-      synced_pref_observers_.find(path);
+  auto observer_iter = synced_pref_observers_.find(path);
   if (observer_iter == synced_pref_observers_.end())
     return;
-  SyncedPrefObserverList* observers = observer_iter->second;
+  SyncedPrefObserverList* observers = observer_iter->second.get();
   FOR_EACH_OBSERVER(SyncedPrefObserver, *observers,
                     OnSyncedPrefChanged(path, from_sync));
 }