Update from https://crrev.com/306655

base/prefs/pref_service.cc

 // 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_service.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 68 matching lines @@
                    user_pref_store_.get(),
                    new ReadErrorHandler(read_error_callback_)));
   }
 }
 
 void PrefService::CommitPendingWrite() {
   DCHECK(CalledOnValidThread());
   user_pref_store_->CommitPendingWrite();
 }
 
-bool PrefService::GetBoolean(const char* path) const {
+bool PrefService::GetBoolean(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   bool result = false;
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return result;
   }
   bool rv = value->GetAsBoolean(&result);
   DCHECK(rv);
   return result;
 }
 
-int PrefService::GetInteger(const char* path) const {
+int PrefService::GetInteger(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   int result = 0;
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return result;
   }
   bool rv = value->GetAsInteger(&result);
   DCHECK(rv);
   return result;
 }
 
-double PrefService::GetDouble(const char* path) const {
+double PrefService::GetDouble(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   double result = 0.0;
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return result;
   }
   bool rv = value->GetAsDouble(&result);
   DCHECK(rv);
   return result;
 }
 
-std::string PrefService::GetString(const char* path) const {
+std::string PrefService::GetString(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   std::string result;
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return result;
   }
   bool rv = value->GetAsString(&result);
   DCHECK(rv);
   return result;
 }
 
-base::FilePath PrefService::GetFilePath(const char* path) const {
+base::FilePath PrefService::GetFilePath(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   base::FilePath result;
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return base::FilePath(result);
   }
   bool rv = base::GetValueAsFilePath(*value, &result);
   DCHECK(rv);
   return result;
 }
 
-bool PrefService::HasPrefPath(const char* path) const {
+bool PrefService::HasPrefPath(const std::string& path) const {
   const Preference* pref = FindPreference(path);
   return pref && !pref->IsDefaultValue();
 }
 
 scoped_ptr<base::DictionaryValue> PrefService::GetPreferenceValues() const {
   DCHECK(CalledOnValidThread());
   scoped_ptr<base::DictionaryValue> out(new base::DictionaryValue);
-  PrefRegistry::const_iterator i = pref_registry_->begin();
-  for (; i != pref_registry_->end(); ++i) {
-    const base::Value* value = GetPreferenceValue(i->first);
-    DCHECK(value);
-    out->Set(i->first, value->DeepCopy());
+  for (const auto& it : *pref_registry_) {
+    const base::Value* value = GetPreferenceValue(it.first);
+    out->Set(it.first, value->DeepCopy());
   }
   return out.Pass();
 }
+
+scoped_ptr<base::DictionaryValue> PrefService::GetPreferenceValuesOmitDefaults()
+    const {
+  DCHECK(CalledOnValidThread());
+  scoped_ptr<base::DictionaryValue> out(new base::DictionaryValue);
+  for (const auto& it : *pref_registry_) {
+    const Preference* pref = FindPreference(it.first);
+    if (pref->IsDefaultValue())
+      continue;
+    out->Set(it.first, pref->GetValue()->DeepCopy());
+  }
+  return out.Pass();
+}
 
 scoped_ptr<base::DictionaryValue>
 PrefService::GetPreferenceValuesWithoutPathExpansion() const {
   DCHECK(CalledOnValidThread());
   scoped_ptr<base::DictionaryValue> out(new base::DictionaryValue);
-  PrefRegistry::const_iterator i = pref_registry_->begin();
-  for (; i != pref_registry_->end(); ++i) {
-    const base::Value* value = GetPreferenceValue(i->first);
+  for (const auto& it : *pref_registry_) {
+    const base::Value* value = GetPreferenceValue(it.first);
     DCHECK(value);
-    out->SetWithoutPathExpansion(i->first, value->DeepCopy());
+    out->SetWithoutPathExpansion(it.first, value->DeepCopy());
   }
   return out.Pass();
 }
 
 const PrefService::Preference* PrefService::FindPreference(
-    const char* pref_name) const {
+    const std::string& pref_name) const {
   DCHECK(CalledOnValidThread());
   PreferenceMap::iterator it = prefs_map_.find(pref_name);
   if (it != prefs_map_.end())
     return &(it->second);
   const base::Value* default_value = NULL;
   if (!pref_registry_->defaults()->GetValue(pref_name, &default_value))
     return NULL;
   it = prefs_map_.insert(
       std::make_pair(pref_name, Preference(
           this, pref_name, default_value->GetType()))).first;
@@ skipping 12 matching lines @@
   switch (user_pref_store_->GetReadError()) {
     case PersistentPrefStore::PREF_READ_ERROR_NONE:
       return INITIALIZATION_STATUS_SUCCESS;
     case PersistentPrefStore::PREF_READ_ERROR_NO_FILE:
       return INITIALIZATION_STATUS_CREATED_NEW_PREF_STORE;
     default:
       return INITIALIZATION_STATUS_ERROR;
   }
 }
 
-bool PrefService::IsManagedPreference(const char* pref_name) const {
+bool PrefService::IsManagedPreference(const std::string& pref_name) const {
   const Preference* pref = FindPreference(pref_name);
   return pref && pref->IsManaged();
 }
 
-bool PrefService::IsUserModifiablePreference(const char* pref_name) const {
+bool PrefService::IsUserModifiablePreference(
+    const std::string& pref_name) const {
   const Preference* pref = FindPreference(pref_name);
   return pref && pref->IsUserModifiable();
 }
 
 const base::DictionaryValue* PrefService::GetDictionary(
-    const char* path) const {
+    const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return NULL;
   }
   if (value->GetType() != base::Value::TYPE_DICTIONARY) {
     NOTREACHED();
     return NULL;
   }
   return static_cast<const base::DictionaryValue*>(value);
 }
 
-const base::Value* PrefService::GetUserPrefValue(const char* path) const {
+const base::Value* PrefService::GetUserPrefValue(
+    const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to get an unregistered pref: " << path;
     return NULL;
   }
 
   // Look for an existing preference in the user store. If it doesn't
   // exist, return NULL.
   base::Value* value = NULL;
   if (!user_pref_store_->GetMutableValue(path, &value))
     return NULL;
 
   if (!value->IsType(pref->GetType())) {
     NOTREACHED() << "Pref value type doesn't match registered type.";
     return NULL;
   }
 
   return value;
 }
 
-void PrefService::SetDefaultPrefValue(const char* path,
+void PrefService::SetDefaultPrefValue(const std::string& path,
                                       base::Value* value) {
   DCHECK(CalledOnValidThread());
   pref_registry_->SetDefaultPrefValue(path, value);
 }
 
-const base::Value* PrefService::GetDefaultPrefValue(const char* path) const {
+const base::Value* PrefService::GetDefaultPrefValue(
+    const std::string& path) const {
   DCHECK(CalledOnValidThread());
   // Lookup the preference in the default store.
   const base::Value* value = NULL;
   if (!pref_registry_->defaults()->GetValue(path, &value)) {
     NOTREACHED() << "Default value missing for pref: " << path;
     return NULL;
   }
   return value;
 }
 
-const base::ListValue* PrefService::GetList(const char* path) const {
+const base::ListValue* PrefService::GetList(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return NULL;
   }
   if (value->GetType() != base::Value::TYPE_LIST) {
     NOTREACHED();
     return NULL;
   }
   return static_cast<const base::ListValue*>(value);
 }
 
-void PrefService::AddPrefObserver(const char* path, PrefObserver* obs) {
+void PrefService::AddPrefObserver(const std::string& path, PrefObserver* obs) {
   pref_notifier_->AddPrefObserver(path, obs);
 }
 
-void PrefService::RemovePrefObserver(const char* path, PrefObserver* obs) {
+void PrefService::RemovePrefObserver(const std::string& path,
+                                     PrefObserver* obs) {
   pref_notifier_->RemovePrefObserver(path, obs);
 }
 
 void PrefService::AddPrefInitObserver(base::Callback<void(bool)> obs) {
   pref_notifier_->AddInitObserver(obs);
 }
 
 PrefRegistry* PrefService::DeprecatedGetPrefRegistry() {
   return pref_registry_.get();
 }
 
-void PrefService::ClearPref(const char* path) {
+void PrefService::ClearPref(const std::string& path) {
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to clear an unregistered pref: " << path;
     return;
   }
   user_pref_store_->RemoveValue(path);
 }
 
-void PrefService::Set(const char* path, const base::Value& value) {
+void PrefService::Set(const std::string& path, const base::Value& value) {
   SetUserPrefValue(path, value.DeepCopy());
 }
 
-void PrefService::SetBoolean(const char* path, bool value) {
+void PrefService::SetBoolean(const std::string& path, bool value) {
   SetUserPrefValue(path, new base::FundamentalValue(value));
 }
 
-void PrefService::SetInteger(const char* path, int value) {
+void PrefService::SetInteger(const std::string& path, int value) {
   SetUserPrefValue(path, new base::FundamentalValue(value));
 }
 
-void PrefService::SetDouble(const char* path, double value) {
+void PrefService::SetDouble(const std::string& path, double value) {
   SetUserPrefValue(path, new base::FundamentalValue(value));
 }
 
-void PrefService::SetString(const char* path, const std::string& value) {
+void PrefService::SetString(const std::string& path, const std::string& value) {
   SetUserPrefValue(path, new base::StringValue(value));
 }
 
-void PrefService::SetFilePath(const char* path, const base::FilePath& value) {
+void PrefService::SetFilePath(const std::string& path,
+                              const base::FilePath& value) {
   SetUserPrefValue(path, base::CreateFilePathValue(value));
 }
 
-void PrefService::SetInt64(const char* path, int64 value) {
+void PrefService::SetInt64(const std::string& path, int64 value) {
   SetUserPrefValue(path, new base::StringValue(base::Int64ToString(value)));
 }
 
-int64 PrefService::GetInt64(const char* path) const {
+int64 PrefService::GetInt64(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return 0;
   }
   std::string result("0");
   bool rv = value->GetAsString(&result);
   DCHECK(rv);
 
   int64 val;
   base::StringToInt64(result, &val);
   return val;
 }
 
-void PrefService::SetUint64(const char* path, uint64 value) {
+void PrefService::SetUint64(const std::string& path, uint64 value) {
   SetUserPrefValue(path, new base::StringValue(base::Uint64ToString(value)));
 }
 
-uint64 PrefService::GetUint64(const char* path) const {
+uint64 PrefService::GetUint64(const std::string& path) const {
   DCHECK(CalledOnValidThread());
 
   const base::Value* value = GetPreferenceValue(path);
   if (!value) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return 0;
   }
   std::string result("0");
   bool rv = value->GetAsString(&result);
   DCHECK(rv);
 
   uint64 val;
   base::StringToUint64(result, &val);
   return val;
 }
 
-base::Value* PrefService::GetMutableUserPref(const char* path,
+base::Value* PrefService::GetMutableUserPref(const std::string& path,
                                              base::Value::Type type) {
   CHECK(type == base::Value::TYPE_DICTIONARY || type == base::Value::TYPE_LIST);
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to get an unregistered pref: " << path;
     return NULL;
   }
   if (pref->GetType() != type) {
@@ skipping 16 matching lines @@
     user_pref_store_->SetValueSilently(path, value);
   }
   return value;
 }
 
 void PrefService::ReportUserPrefChanged(const std::string& key) {
   DCHECK(CalledOnValidThread());
   user_pref_store_->ReportValueChanged(key);
 }
 
-void PrefService::SetUserPrefValue(const char* path, base::Value* new_value) {
+void PrefService::SetUserPrefValue(const std::string& path,
+                                   base::Value* new_value) {
   scoped_ptr<base::Value> owned_value(new_value);
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to write an unregistered pref: " << path;
     return;
   }
   if (pref->GetType() != new_value->GetType()) {
     NOTREACHED() << "Trying to set pref " << path
                  << " of type " << pref->GetType()
                  << " to value of type " << new_value->GetType();
     return;
   }
 
   user_pref_store_->SetValue(path, owned_value.release());
 }
 
 void PrefService::UpdateCommandLinePrefStore(PrefStore* command_line_store) {
   pref_value_store_->UpdateCommandLinePrefStore(command_line_store);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // PrefService::Preference
 
 PrefService::Preference::Preference(const PrefService* service,
-                                    const char* name,
+                                    const std::string& name,
                                     base::Value::Type type)
-      : name_(name),
-        type_(type),
-        pref_service_(service) {
-  DCHECK(name);
+    : name_(name), type_(type), pref_service_(service) {
   DCHECK(service);
 }
 
 const std::string PrefService::Preference::name() const {
   return name_;
 }
 
 base::Value::Type PrefService::Preference::GetType() const {
   return type_;
 }
 
 const base::Value* PrefService::Preference::GetValue() const {
   const base::Value* result= pref_service_->GetPreferenceValue(name_);
   DCHECK(result) << "Must register pref before getting its value";
   return result;
 }
 
 const base::Value* PrefService::Preference::GetRecommendedValue() const {
-  DCHECK(pref_service_->FindPreference(name_.c_str())) <<
-      "Must register pref before getting its value";
+  DCHECK(pref_service_->FindPreference(name_))
+      << "Must register pref before getting its value";
 
   const base::Value* found_value = NULL;
   if (pref_value_store()->GetRecommendedValue(name_, type_, &found_value)) {
     DCHECK(found_value->IsType(type_));
     return found_value;
   }
 
   // The pref has no recommended value.
   return NULL;
 }
 
 bool PrefService::Preference::IsManaged() const {
-  return pref_value_store()->PrefValueInManagedStore(name_.c_str());
+  return pref_value_store()->PrefValueInManagedStore(name_);
 }
 
 bool PrefService::Preference::IsRecommended() const {
-  return pref_value_store()->PrefValueFromRecommendedStore(name_.c_str());
+  return pref_value_store()->PrefValueFromRecommendedStore(name_);
 }
 
 bool PrefService::Preference::HasExtensionSetting() const {
-  return pref_value_store()->PrefValueInExtensionStore(name_.c_str());
+  return pref_value_store()->PrefValueInExtensionStore(name_);
 }
 
 bool PrefService::Preference::HasUserSetting() const {
-  return pref_value_store()->PrefValueInUserStore(name_.c_str());
+  return pref_value_store()->PrefValueInUserStore(name_);
 }
 
 bool PrefService::Preference::IsExtensionControlled() const {
-  return pref_value_store()->PrefValueFromExtensionStore(name_.c_str());
+  return pref_value_store()->PrefValueFromExtensionStore(name_);
 }
 
 bool PrefService::Preference::IsUserControlled() const {
-  return pref_value_store()->PrefValueFromUserStore(name_.c_str());
+  return pref_value_store()->PrefValueFromUserStore(name_);
 }
 
 bool PrefService::Preference::IsDefaultValue() const {
-  return pref_value_store()->PrefValueFromDefaultStore(name_.c_str());
+  return pref_value_store()->PrefValueFromDefaultStore(name_);
 }
 
 bool PrefService::Preference::IsUserModifiable() const {
-  return pref_value_store()->PrefValueUserModifiable(name_.c_str());
+  return pref_value_store()->PrefValueUserModifiable(name_);
 }
 
 bool PrefService::Preference::IsExtensionModifiable() const {
-  return pref_value_store()->PrefValueExtensionModifiable(name_.c_str());
+  return pref_value_store()->PrefValueExtensionModifiable(name_);
 }
 
 const base::Value* PrefService::GetPreferenceValue(
     const std::string& path) const {
   DCHECK(CalledOnValidThread());
   const base::Value* default_value = NULL;
   if (pref_registry_->defaults()->GetValue(path, &default_value)) {
     const base::Value* found_value = NULL;
     base::Value::Type default_type = default_value->GetType();
     if (pref_value_store_->GetValue(path, default_type, &found_value)) {
       DCHECK(found_value->IsType(default_type));
       return found_value;
     } else {
       // Every registered preference has at least a default value.
       NOTREACHED() << "no valid value found for registered pref " << path;
     }
   }
 
   return NULL;
 }