Revert "Rewrite std::string("") to std::string(), Linux edition."

This reverts commit e59558b78e8c6a1b0bd916a724724b638c3c91b6.

Revert "Fix build after r193020."

This reverts commit 558a35897f6b3ffbcaefde927c1f150b815d140a.

Revert "Really fix build after r193020."

This reverts commit e3748a79b523a8d365d4a33ef986eebb4186fa78.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193030 0039d316-1c4b-4281-b951-d872f2087c98

15 files changed, 327 insertions, 409 deletions

diff --git a/chrome/browser/content_settings/content_settings_browsertest.cc b/chrome/browser/content_settings/content_settings_browsertest.cc
index f4105ad..88c664c 100644
--- a/chrome/browser/content_settings/content_settings_browsertest.cc
+++ b/chrome/browser/content_settings/content_settings_browsertest.cc
@@ -338,12 +338,12 @@ IN_PROC_BROWSER_TEST_F(ClickToPlayPluginTest, AllowException) {
 
   browser()->profile()->GetHostContentSettingsMap()->SetDefaultContentSetting(
       CONTENT_SETTINGS_TYPE_PLUGINS, CONTENT_SETTING_BLOCK);
-  browser()->profile()->GetHostContentSettingsMap()
-      ->SetContentSetting(ContentSettingsPattern::FromURL(url),
-                          ContentSettingsPattern::Wildcard(),
-                          CONTENT_SETTINGS_TYPE_PLUGINS,
-                          std::string(),
-                          CONTENT_SETTING_ALLOW);
+  browser()->profile()->GetHostContentSettingsMap()->SetContentSetting(
+      ContentSettingsPattern::FromURL(url),
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_PLUGINS,
+      "",
+      CONTENT_SETTING_ALLOW);
 
   string16 expected_title(ASCIIToUTF16("OK"));
   content::TitleWatcher title_watcher(
@@ -357,12 +357,12 @@ IN_PROC_BROWSER_TEST_F(ClickToPlayPluginTest, BlockException) {
   GURL url = ui_test_utils::GetTestUrl(
       base::FilePath(), base::FilePath().AppendASCII("clicktoplay.html"));
 
-  browser()->profile()->GetHostContentSettingsMap()
-      ->SetContentSetting(ContentSettingsPattern::FromURL(url),
-                          ContentSettingsPattern::Wildcard(),
-                          CONTENT_SETTINGS_TYPE_PLUGINS,
-                          std::string(),
-                          CONTENT_SETTING_BLOCK);
+  browser()->profile()->GetHostContentSettingsMap()->SetContentSetting(
+      ContentSettingsPattern::FromURL(url),
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_PLUGINS,
+      "",
+      CONTENT_SETTING_BLOCK);
 
   string16 expected_title(ASCIIToUTF16("Click To Play"));
   content::TitleWatcher title_watcher(
diff --git a/chrome/browser/content_settings/content_settings_internal_extension_provider.cc b/chrome/browser/content_settings/content_settings_internal_extension_provider.cc
index 56dd993..815d037 100644
--- a/chrome/browser/content_settings/content_settings_internal_extension_provider.cc
+++ b/chrome/browser/content_settings/content_settings_internal_extension_provider.cc
@@ -117,19 +117,19 @@ void InternalExtensionProvider::SetContentSettingForExtension(
       value_map_.DeleteValue(primary_pattern,
                              secondary_pattern,
                              CONTENT_SETTINGS_TYPE_PLUGINS,
-                             ResourceIdentifier());
+                             ResourceIdentifier(""));
     } else {
       value_map_.SetValue(primary_pattern,
                           secondary_pattern,
                           CONTENT_SETTINGS_TYPE_PLUGINS,
-                          ResourceIdentifier(),
+                          ResourceIdentifier(""),
                           Value::CreateIntegerValue(setting));
     }
   }
   NotifyObservers(primary_pattern,
                   secondary_pattern,
                   CONTENT_SETTINGS_TYPE_PLUGINS,
-                  ResourceIdentifier());
+                  ResourceIdentifier(""));
 }
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_origin_identifier_value_map_unittest.cc b/chrome/browser/content_settings/content_settings_origin_identifier_value_map_unittest.cc
index b8612a5..21089fb 100644
--- a/chrome/browser/content_settings/content_settings_origin_identifier_value_map_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_origin_identifier_value_map_unittest.cc
@@ -14,40 +14,38 @@
 TEST(OriginIdentifierValueMapTest, SetGetValue) {
   content_settings::OriginIdentifierValueMap map;
 
-  EXPECT_EQ(NULL,
-            map.GetValue(GURL("http://www.google.com"),
-                         GURL("http://www.google.com"),
-                         CONTENT_SETTINGS_TYPE_COOKIES,
-                         std::string()));
-  map.SetValue(ContentSettingsPattern::FromString("[*.]google.com"),
-               ContentSettingsPattern::FromString("[*.]google.com"),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(1));
+  EXPECT_EQ(NULL, map.GetValue(GURL("http://www.google.com"),
+                               GURL("http://www.google.com"),
+                               CONTENT_SETTINGS_TYPE_COOKIES,
+                               ""));
+  map.SetValue(
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(1));
 
   scoped_ptr<Value> expected_value(Value::CreateIntegerValue(1));
-  EXPECT_TRUE(expected_value->Equals(map.GetValue(GURL("http://www.google.com"),
-                                                  GURL("http://www.google.com"),
-                                                  CONTENT_SETTINGS_TYPE_COOKIES,
-                                                  std::string())));
-
-  EXPECT_EQ(NULL,
-            map.GetValue(GURL("http://www.google.com"),
-                         GURL("http://www.youtube.com"),
-                         CONTENT_SETTINGS_TYPE_COOKIES,
-                         std::string()));
-
-  EXPECT_EQ(NULL,
-            map.GetValue(GURL("http://www.youtube.com"),
-                         GURL("http://www.google.com"),
-                         CONTENT_SETTINGS_TYPE_COOKIES,
-                         std::string()));
-
-  EXPECT_EQ(NULL,
-            map.GetValue(GURL("http://www.google.com"),
-                         GURL("http://www.google.com"),
-                         CONTENT_SETTINGS_TYPE_POPUPS,
-                         std::string()));
+  EXPECT_TRUE(expected_value->Equals(
+      map.GetValue(GURL("http://www.google.com"),
+                   GURL("http://www.google.com"),
+                   CONTENT_SETTINGS_TYPE_COOKIES,
+                   "")));
+
+  EXPECT_EQ(NULL, map.GetValue(GURL("http://www.google.com"),
+                               GURL("http://www.youtube.com"),
+                               CONTENT_SETTINGS_TYPE_COOKIES,
+                               ""));
+
+  EXPECT_EQ(NULL, map.GetValue(GURL("http://www.youtube.com"),
+                               GURL("http://www.google.com"),
+                               CONTENT_SETTINGS_TYPE_COOKIES,
+                               ""));
+
+  EXPECT_EQ(NULL, map.GetValue(GURL("http://www.google.com"),
+                               GURL("http://www.google.com"),
+                               CONTENT_SETTINGS_TYPE_POPUPS,
+                               ""));
 
   EXPECT_EQ(NULL, map.GetValue(GURL("http://www.google.com"),
                                GURL("http://www.google.com"),
@@ -121,11 +119,12 @@ TEST(OriginIdentifierValueMapTest, Clear) {
       CONTENT_SETTINGS_TYPE_PLUGINS,
       "java-plugin",
       Value::CreateIntegerValue(1));
-  map.SetValue(ContentSettingsPattern::FromString("[*.]google.com"),
-               ContentSettingsPattern::FromString("[*.]google.com"),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(1));
+  map.SetValue(
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(1));
   EXPECT_FALSE(map.empty());
   int actual_value;
   EXPECT_TRUE(map.GetValue(GURL("http://www.google.com"),
@@ -146,36 +145,38 @@ TEST(OriginIdentifierValueMapTest, Clear) {
 TEST(OriginIdentifierValueMapTest, ListEntryPrecedences) {
   content_settings::OriginIdentifierValueMap map;
 
-  map.SetValue(ContentSettingsPattern::FromString("[*.]google.com"),
-               ContentSettingsPattern::FromString("[*.]google.com"),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(1));
+  map.SetValue(
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(1));
 
-  map.SetValue(ContentSettingsPattern::FromString("www.google.com"),
-               ContentSettingsPattern::FromString("[*.]google.com"),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(2));
+  map.SetValue(
+      ContentSettingsPattern::FromString("www.google.com"),
+      ContentSettingsPattern::FromString("[*.]google.com"),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(2));
 
   int actual_value;
   EXPECT_TRUE(map.GetValue(GURL("http://mail.google.com"),
                            GURL("http://www.google.com"),
                            CONTENT_SETTINGS_TYPE_COOKIES,
-                           std::string())->GetAsInteger(&actual_value));
+                           "")->GetAsInteger(&actual_value));
   EXPECT_EQ(1, actual_value);
 
   EXPECT_TRUE(map.GetValue(GURL("http://www.google.com"),
                            GURL("http://www.google.com"),
                            CONTENT_SETTINGS_TYPE_COOKIES,
-                           std::string())->GetAsInteger(&actual_value));
+                           "")->GetAsInteger(&actual_value));
   EXPECT_EQ(2, actual_value);
 }
 
 TEST(OriginIdentifierValueMapTest, IterateEmpty) {
   content_settings::OriginIdentifierValueMap map;
   scoped_ptr<content_settings::RuleIterator> rule_iterator(
-      map.GetRuleIterator(CONTENT_SETTINGS_TYPE_COOKIES, std::string(), NULL));
+      map.GetRuleIterator(CONTENT_SETTINGS_TYPE_COOKIES, "", NULL));
   EXPECT_FALSE(rule_iterator->HasNext());
 }
 
@@ -186,19 +187,21 @@ TEST(OriginIdentifierValueMapTest, IterateNonempty) {
       ContentSettingsPattern::FromString("[*.]google.com");
   ContentSettingsPattern sub_pattern =
       ContentSettingsPattern::FromString("sub.google.com");
-  map.SetValue(pattern,
-               ContentSettingsPattern::Wildcard(),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(1));
-  map.SetValue(sub_pattern,
-               ContentSettingsPattern::Wildcard(),
-               CONTENT_SETTINGS_TYPE_COOKIES,
-               std::string(),
-               Value::CreateIntegerValue(2));
+  map.SetValue(
+      pattern,
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(1));
+  map.SetValue(
+      sub_pattern,
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      Value::CreateIntegerValue(2));
 
   scoped_ptr<content_settings::RuleIterator> rule_iterator(
-      map.GetRuleIterator(CONTENT_SETTINGS_TYPE_COOKIES, std::string(), NULL));
+      map.GetRuleIterator(CONTENT_SETTINGS_TYPE_COOKIES, "", NULL));
   ASSERT_TRUE(rule_iterator->HasNext());
   content_settings::Rule rule = rule_iterator->Next();
   EXPECT_EQ(sub_pattern, rule.primary_pattern);
diff --git a/chrome/browser/content_settings/content_settings_policy_provider.cc b/chrome/browser/content_settings/content_settings_policy_provider.cc
index f1e40fb..b112db0 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider.cc
+++ b/chrome/browser/content_settings/content_settings_policy_provider.cc
@@ -276,7 +276,7 @@ void PolicyProvider::GetContentSettingsFromPreferences(
           pattern_pair.first,
           secondary_pattern,
           content_type,
-          NO_RESOURCE_IDENTIFIER,
+          ResourceIdentifier(NO_RESOURCE_IDENTIFIER),
           base::Value::CreateIntegerValue(
               kPrefsForManagedContentSettingsMap[i].setting));
     }
diff --git a/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc b/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
index 37b718c..23c43f8 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
@@ -150,34 +150,22 @@ TEST_F(PolicyProviderTest, GettingManagedContentSettings) {
   GURL google_url("http://mail.google.com");
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&provider,
-                              youtube_url,
-                              youtube_url,
-                              CONTENT_SETTINGS_TYPE_COOKIES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &provider, youtube_url, youtube_url,
+                CONTENT_SETTINGS_TYPE_COOKIES, "", false));
   EXPECT_EQ(NULL,
-            GetContentSettingValue(&provider,
-                                   youtube_url,
-                                   youtube_url,
-                                   CONTENT_SETTINGS_TYPE_COOKIES,
-                                   std::string(),
-                                   false));
+            GetContentSettingValue(
+                &provider, youtube_url, youtube_url,
+                CONTENT_SETTINGS_TYPE_COOKIES, "", false));
 
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&provider,
-                              google_url,
-                              google_url,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &provider, google_url, google_url,
+                CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   scoped_ptr<Value> value_ptr(
-      GetContentSettingValue(&provider,
-                             google_url,
-                             google_url,
-                             CONTENT_SETTINGS_TYPE_IMAGES,
-                             std::string(),
-                             false));
+      GetContentSettingValue(
+          &provider, google_url, google_url,
+          CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
   int int_value = -1;
   value_ptr->GetAsInteger(&int_value);
@@ -188,19 +176,17 @@ TEST_F(PolicyProviderTest, GettingManagedContentSettings) {
   // SetWebsiteSetting does nothing.
   scoped_ptr<base::Value> value_block(
       Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
-  bool owned = provider.SetWebsiteSetting(yt_url_pattern,
-                                          yt_url_pattern,
-                                          CONTENT_SETTINGS_TYPE_COOKIES,
-                                          std::string(),
-                                          value_block.get());
+  bool owned = provider.SetWebsiteSetting(
+      yt_url_pattern,
+      yt_url_pattern,
+      CONTENT_SETTINGS_TYPE_COOKIES,
+      "",
+      value_block.get());
   EXPECT_FALSE(owned);
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&provider,
-                              youtube_url,
-                              youtube_url,
-                              CONTENT_SETTINGS_TYPE_COOKIES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &provider, youtube_url, youtube_url,
+                CONTENT_SETTINGS_TYPE_COOKIES, "", false));
 
   provider.ShutdownOnUIThread();
 }
@@ -227,12 +213,9 @@ TEST_F(PolicyProviderTest, ResourceIdentifier) {
   // There is currently no policy support for resource content settings.
   // Resource identifiers are simply ignored by the PolicyProvider.
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            GetContentSetting(&provider,
-                              google_url,
-                              google_url,
-                              CONTENT_SETTINGS_TYPE_PLUGINS,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &provider, google_url, google_url,
+                CONTENT_SETTINGS_TYPE_PLUGINS, "", false));
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
             GetContentSetting(
@@ -249,14 +232,10 @@ TEST_F(PolicyProviderTest, AutoSelectCertificateList) {
   PolicyProvider provider(prefs);
   GURL google_url("https://mail.google.com");
   // Tests the default setting for auto selecting certificates
-  EXPECT_EQ(
-      NULL,
-      GetContentSettingValue(&provider,
-                             google_url,
-                             google_url,
-                             CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE,
-                             std::string(),
-                             false));
+  EXPECT_EQ(NULL,
+            GetContentSettingValue(
+                &provider, google_url, google_url,
+                CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE, "", false));
 
   // Set the content settings pattern list for origins to auto select
   // certificates.
@@ -268,21 +247,13 @@ TEST_F(PolicyProviderTest, AutoSelectCertificateList) {
   prefs->SetManagedPref(prefs::kManagedAutoSelectCertificateForUrls,
                         value);
   GURL youtube_url("https://www.youtube.com");
-  EXPECT_EQ(
-      NULL,
-      GetContentSettingValue(&provider,
-                             youtube_url,
-                             youtube_url,
-                             CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE,
-                             std::string(),
-                             false));
-  scoped_ptr<Value> cert_filter(
-      GetContentSettingValue(&provider,
-                             google_url,
-                             google_url,
-                             CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE,
-                             std::string(),
-                             false));
+  EXPECT_EQ(NULL,
+            GetContentSettingValue(
+                &provider, youtube_url, youtube_url,
+                CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE, "", false));
+  scoped_ptr<Value> cert_filter(GetContentSettingValue(
+      &provider, google_url, google_url,
+      CONTENT_SETTINGS_TYPE_AUTO_SELECT_CERTIFICATE, "", false));
 
   ASSERT_EQ(Value::TYPE_DICTIONARY, cert_filter->GetType());
   DictionaryValue* dict_value =
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.cc b/chrome/browser/content_settings/content_settings_pref_provider.cc
index 4690f2f..a92315e 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider.cc
@@ -188,21 +188,22 @@ void PrefProvider::ClearAllContentSettingsRules(
   {
     base::AutoLock auto_lock(lock_);
     scoped_ptr<RuleIterator> rule_iterator(
-        map_to_modify->GetRuleIterator(content_type, std::string(), NULL));
+        map_to_modify->GetRuleIterator(content_type, "", NULL));
     // Copy the rules; we cannot call |UpdatePref| while holding |lock_|.
     while (rule_iterator->HasNext())
       rules_to_delete.push_back(rule_iterator->Next());
 
-    map_to_modify->DeleteValues(content_type, std::string());
+    map_to_modify->DeleteValues(content_type, "");
   }
 
   for (std::vector<Rule>::const_iterator it = rules_to_delete.begin();
        it != rules_to_delete.end(); ++it) {
-    UpdatePref(it->primary_pattern,
-               it->secondary_pattern,
-               content_type,
-               std::string(),
-               NULL);
+    UpdatePref(
+        it->primary_pattern,
+        it->secondary_pattern,
+        content_type,
+        "",
+        NULL);
   }
   NotifyObservers(ContentSettingsPattern(),
                   ContentSettingsPattern(),
@@ -306,8 +307,8 @@ void PrefProvider::UpdatePref(
 void PrefProvider::MigrateObsoleteMediaContentSetting() {
   std::vector<Rule> rules_to_delete;
   {
-    scoped_ptr<RuleIterator> rule_iterator(GetRuleIterator(
-        CONTENT_SETTINGS_TYPE_MEDIASTREAM, std::string(), false));
+    scoped_ptr<RuleIterator> rule_iterator(
+        GetRuleIterator(CONTENT_SETTINGS_TYPE_MEDIASTREAM, "", false));
     while (rule_iterator->HasNext()) {
       // Skip default setting and rules without a value.
       const content_settings::Rule& rule = rule_iterator->Next();
@@ -332,7 +333,7 @@ void PrefProvider::MigrateObsoleteMediaContentSetting() {
       SetWebsiteSetting(it->primary_pattern,
                         it->secondary_pattern,
                         CONTENT_SETTINGS_TYPE_MEDIASTREAM_MIC,
-                        std::string(),
+                        "",
                         Value::CreateIntegerValue(CONTENT_SETTING_ALLOW));
     }
     // Add the exception to the new camera content setting.
@@ -340,7 +341,7 @@ void PrefProvider::MigrateObsoleteMediaContentSetting() {
       SetWebsiteSetting(it->primary_pattern,
                         it->secondary_pattern,
                         CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA,
-                        std::string(),
+                        "",
                         Value::CreateIntegerValue(CONTENT_SETTING_ALLOW));
     }
 
@@ -348,7 +349,7 @@ void PrefProvider::MigrateObsoleteMediaContentSetting() {
     SetWebsiteSetting(it->primary_pattern,
                       it->secondary_pattern,
                       CONTENT_SETTINGS_TYPE_MEDIASTREAM,
-                      std::string(),
+                      "",
                       NULL);
   }
 }
@@ -454,7 +455,7 @@ void PrefProvider::ReadContentSettingsFromPref(bool overwrite) {
         value_map_.SetValue(pattern_pair.first,
                             pattern_pair.second,
                             content_type,
-                            ResourceIdentifier(),
+                            ResourceIdentifier(""),
                             value);
         if (content_type == CONTENT_SETTINGS_TYPE_COOKIES) {
           ContentSetting s = ValueToContentSetting(value);
diff --git a/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc b/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
index 1ddc6d0..f951829 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
@@ -121,7 +121,7 @@ TEST_F(PrefProviderTest, Observer) {
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       Value::CreateIntegerValue(CONTENT_SETTING_ALLOW));
 
   pref_content_settings_provider.ShutdownOnUIThread();
@@ -166,26 +166,20 @@ TEST_F(PrefProviderTest, Incognito) {
       pattern,
       pattern,
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       Value::CreateIntegerValue(CONTENT_SETTING_ALLOW));
 
   GURL host("http://example.com/");
   // The value should of course be visible in the regular PrefProvider.
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            GetContentSetting(&pref_content_settings_provider,
-                              host,
-                              host,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   // And also in the OTR version.
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            GetContentSetting(&pref_content_settings_provider_incognito,
-                              host,
-                              host,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider_incognito,
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   // But the value should not be overridden in the OTR user prefs accidentally.
   EXPECT_FALSE(otr_user_prefs->IsSetInOverlay(
       prefs::kContentSettingsPatternPairs));
@@ -203,40 +197,26 @@ TEST_F(PrefProviderTest, GetContentSettingsValue) {
       ContentSettingsPattern::FromString("[*.]example.com");
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&provider,
-                              primary_url,
-                              primary_url,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(&provider, primary_url, primary_url,
+                              CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
   EXPECT_EQ(NULL,
-            GetContentSettingValue(&provider,
-                                   primary_url,
-                                   primary_url,
-                                   CONTENT_SETTINGS_TYPE_IMAGES,
-                                   std::string(),
-                                   false));
+            GetContentSettingValue(
+                &provider, primary_url, primary_url,
+                CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
-  provider.SetWebsiteSetting(primary_pattern,
-                             primary_pattern,
-                             CONTENT_SETTINGS_TYPE_IMAGES,
-                             std::string(),
-                             Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
+  provider.SetWebsiteSetting(
+      primary_pattern,
+      primary_pattern,
+      CONTENT_SETTINGS_TYPE_IMAGES,
+      "",
+      Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&provider,
-                              primary_url,
-                              primary_url,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(&provider, primary_url, primary_url,
+                              CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   scoped_ptr<Value> value_ptr(
-      GetContentSettingValue(&provider,
-                             primary_url,
-                             primary_url,
-                             CONTENT_SETTINGS_TYPE_IMAGES,
-                             std::string(),
-                             false));
+      GetContentSettingValue(&provider, primary_url, primary_url,
+                             CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   int int_value = -1;
   value_ptr->GetAsInteger(&int_value);
   EXPECT_EQ(CONTENT_SETTING_BLOCK, IntToContentSetting(int_value));
@@ -244,15 +224,12 @@ TEST_F(PrefProviderTest, GetContentSettingsValue) {
   provider.SetWebsiteSetting(primary_pattern,
                              primary_pattern,
                              CONTENT_SETTINGS_TYPE_IMAGES,
-                             std::string(),
+                             "",
                              NULL);
   EXPECT_EQ(NULL,
-            GetContentSettingValue(&provider,
-                                   primary_url,
-                                   primary_url,
-                                   CONTENT_SETTINGS_TYPE_IMAGES,
-                                   std::string(),
-                                   false));
+            GetContentSettingValue(
+                &provider, primary_url, primary_url,
+                CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   provider.ShutdownOnUIThread();
 }
 
@@ -273,74 +250,53 @@ TEST_F(PrefProviderTest, Patterns) {
       ContentSettingsPattern::FromString("file:///tmp/test.html");
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&pref_content_settings_provider,
-                              host1,
-                              host1,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   pref_content_settings_provider.SetWebsiteSetting(
       pattern1,
       pattern1,
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&pref_content_settings_provider,
-                              host1,
-                              host1,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&pref_content_settings_provider,
-                              host2,
-                              host2,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host2, host2, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&pref_content_settings_provider,
-                              host3,
-                              host3,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
   pref_content_settings_provider.SetWebsiteSetting(
       pattern2,
       pattern2,
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&pref_content_settings_provider,
-                              host3,
-                              host3,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
             GetContentSetting(&pref_content_settings_provider,
-                              host4,
-                              host4,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
+                              host4, host4, CONTENT_SETTINGS_TYPE_IMAGES, "",
                               false));
   pref_content_settings_provider.SetWebsiteSetting(
       pattern3,
       pattern3,
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            GetContentSetting(&pref_content_settings_provider,
-                              host4,
-                              host4,
-                              CONTENT_SETTINGS_TYPE_IMAGES,
-                              std::string(),
-                              false));
+            GetContentSetting(
+                &pref_content_settings_provider,
+                host4, host4, CONTENT_SETTINGS_TYPE_IMAGES, "", false));
 
   pref_content_settings_provider.ShutdownOnUIThread();
 }
diff --git a/chrome/browser/content_settings/content_settings_provider.h b/chrome/browser/content_settings/content_settings_provider.h
index 6bc64de..fefa226 100644
--- a/chrome/browser/content_settings/content_settings_provider.h
+++ b/chrome/browser/content_settings/content_settings_provider.h
@@ -7,7 +7,7 @@
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PROVIDER_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PROVIDER_H_
 
-#define NO_RESOURCE_IDENTIFIER std::string()
+#define NO_RESOURCE_IDENTIFIER ""
 
 #include <string>
 #include <vector>
diff --git a/chrome/browser/content_settings/content_settings_provider_unittest.cc b/chrome/browser/content_settings/content_settings_provider_unittest.cc
index 0832a1c..e0857b3 100644
--- a/chrome/browser/content_settings/content_settings_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_provider_unittest.cc
@@ -46,18 +46,11 @@ TEST(ContentSettingsProviderTest, Mock) {
                                    CONTENT_SETTINGS_TYPE_PLUGINS,
                                    "flash_plugin", false));
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
-            GetContentSetting(&mock_provider,
-                              url,
-                              url,
-                              CONTENT_SETTINGS_TYPE_GEOLOCATION,
-                              std::string(),
-                              false));
+            GetContentSetting(&mock_provider, url, url,
+                              CONTENT_SETTINGS_TYPE_GEOLOCATION, "", false));
   EXPECT_EQ(NULL,
-            GetContentSettingValue(&mock_provider,
-                                   url,
-                                   url,
-                                   CONTENT_SETTINGS_TYPE_GEOLOCATION,
-                                   std::string(),
+            GetContentSettingValue(&mock_provider, url, url,
+                                   CONTENT_SETTINGS_TYPE_GEOLOCATION, "",
                                    false));
 
   bool owned = mock_provider.SetWebsiteSetting(
diff --git a/chrome/browser/content_settings/content_settings_utils.cc b/chrome/browser/content_settings/content_settings_utils.cc
index 9754ba1..d3a2869 100644
--- a/chrome/browser/content_settings/content_settings_utils.cc
+++ b/chrome/browser/content_settings/content_settings_utils.cc
@@ -190,10 +190,10 @@ ContentSetting GetContentSetting(const ProviderInterface* provider,
 
 void GetRendererContentSettingRules(const HostContentSettingsMap* map,
                                     RendererContentSettingRules* rules) {
-  map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_IMAGES, std::string(), &(rules->image_rules));
-  map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string(), &(rules->script_rules));
+  map->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_IMAGES, "",
+                             &(rules->image_rules));
+  map->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_JAVASCRIPT, "",
+                             &(rules->script_rules));
 }
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_utils_unittest.cc b/chrome/browser/content_settings/content_settings_utils_unittest.cc
index d5eeeca..69f88c1 100644
--- a/chrome/browser/content_settings/content_settings_utils_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_utils_unittest.cc
@@ -11,7 +11,7 @@
 TEST(ContentSettingsUtilsTest, ParsePatternString) {
   content_settings::PatternPair pattern_pair;
 
-  pattern_pair = content_settings::ParsePatternString(std::string());
+  pattern_pair = content_settings::ParsePatternString("");
   EXPECT_FALSE(pattern_pair.first.IsValid());
   EXPECT_FALSE(pattern_pair.second.IsValid());
 
diff --git a/chrome/browser/content_settings/cookie_settings.cc b/chrome/browser/content_settings/cookie_settings.cc
index e0b1ff6..e34a56e 100644
--- a/chrome/browser/content_settings/cookie_settings.cc
+++ b/chrome/browser/content_settings/cookie_settings.cc
@@ -130,7 +130,7 @@ bool CookieSettings::IsCookieSessionOnly(const GURL& origin) const {
 void CookieSettings::GetCookieSettings(
     ContentSettingsForOneType* settings) const {
   return host_content_settings_map_->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_COOKIES, std::string(), settings);
+      CONTENT_SETTINGS_TYPE_COOKIES, "", settings);
 }
 
 void CookieSettings::SetDefaultCookieSetting(ContentSetting setting) {
@@ -147,21 +147,17 @@ void CookieSettings::SetCookieSetting(
   if (setting == CONTENT_SETTING_SESSION_ONLY) {
     DCHECK(secondary_pattern == ContentSettingsPattern::Wildcard());
   }
-  host_content_settings_map_->SetContentSetting(primary_pattern,
-                                                secondary_pattern,
-                                                CONTENT_SETTINGS_TYPE_COOKIES,
-                                                std::string(),
-                                                setting);
+  host_content_settings_map_->SetContentSetting(
+      primary_pattern, secondary_pattern, CONTENT_SETTINGS_TYPE_COOKIES, "",
+      setting);
 }
 
 void CookieSettings::ResetCookieSetting(
     const ContentSettingsPattern& primary_pattern,
     const ContentSettingsPattern& secondary_pattern) {
-  host_content_settings_map_->SetContentSetting(primary_pattern,
-                                                secondary_pattern,
-                                                CONTENT_SETTINGS_TYPE_COOKIES,
-                                                std::string(),
-                                                CONTENT_SETTING_DEFAULT);
+  host_content_settings_map_->SetContentSetting(
+      primary_pattern, secondary_pattern, CONTENT_SETTINGS_TYPE_COOKIES, "",
+      CONTENT_SETTING_DEFAULT);
 }
 
 void CookieSettings::ShutdownOnUIThread() {
@@ -180,12 +176,9 @@ ContentSetting CookieSettings::GetCookieSetting(
 
   // First get any host-specific settings.
   content_settings::SettingInfo info;
-  scoped_ptr<base::Value> value(host_content_settings_map_->GetWebsiteSetting(
-      url,
-      first_party_url,
-      CONTENT_SETTINGS_TYPE_COOKIES,
-      std::string(),
-      &info));
+  scoped_ptr<base::Value> value(
+      host_content_settings_map_->GetWebsiteSetting(
+          url, first_party_url, CONTENT_SETTINGS_TYPE_COOKIES, "", &info));
   if (source)
     *source = info.source;
 
diff --git a/chrome/browser/content_settings/host_content_settings_map.cc b/chrome/browser/content_settings/host_content_settings_map.cc
index 777203d..8749d6f 100644
--- a/chrome/browser/content_settings/host_content_settings_map.cc
+++ b/chrome/browser/content_settings/host_content_settings_map.cc
@@ -133,7 +133,7 @@ void HostContentSettingsMap::RegisterExtensionService(
   OnContentSettingChanged(ContentSettingsPattern(),
                           ContentSettingsPattern(),
                           CONTENT_SETTINGS_TYPE_DEFAULT,
-                          std::string());
+                          "");
 }
 #endif
 
@@ -159,7 +159,7 @@ ContentSetting HostContentSettingsMap::GetDefaultContentSettingFromProvider(
     ContentSettingsType content_type,
     content_settings::ProviderInterface* provider) const {
   scoped_ptr<content_settings::RuleIterator> rule_iterator(
-      provider->GetRuleIterator(content_type, std::string(), false));
+      provider->GetRuleIterator(content_type, "", false));
 
   ContentSettingsPattern wildcard = ContentSettingsPattern::Wildcard();
   while (rule_iterator->HasNext()) {
@@ -460,18 +460,19 @@ void HostContentSettingsMap::MigrateObsoleteClearOnExitPref() {
   AddSettingsForOneType(content_settings_providers_[PREF_PROVIDER],
                         PREF_PROVIDER,
                         CONTENT_SETTINGS_TYPE_COOKIES,
-                        std::string(),
+                        "",
                         &exceptions,
                         false);
   for (ContentSettingsForOneType::iterator it = exceptions.begin();
        it != exceptions.end(); ++it) {
     if (it->setting != CONTENT_SETTING_ALLOW)
       continue;
-    SetWebsiteSetting(it->primary_pattern,
-                      it->secondary_pattern,
-                      CONTENT_SETTINGS_TYPE_COOKIES,
-                      std::string(),
-                      Value::CreateIntegerValue(CONTENT_SETTING_SESSION_ONLY));
+    SetWebsiteSetting(
+        it->primary_pattern,
+        it->secondary_pattern,
+        CONTENT_SETTINGS_TYPE_COOKIES,
+        "",
+        Value::CreateIntegerValue(CONTENT_SETTING_SESSION_ONLY));
   }
 
   prefs_->SetBoolean(prefs::kContentSettingsClearOnExitMigrated, true);
diff --git a/chrome/browser/content_settings/host_content_settings_map_unittest.cc b/chrome/browser/content_settings/host_content_settings_map_unittest.cc
index bba4336..57fd929 100644
--- a/chrome/browser/content_settings/host_content_settings_map_unittest.cc
+++ b/chrome/browser/content_settings/host_content_settings_map_unittest.cc
@@ -81,16 +81,16 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
        ContentSettingsPattern::FromString("[*.]example.com");
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
@@ -99,10 +99,10 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, ""));
 
   // Check returning all settings for a host.
   host_content_settings_map->SetContentSetting(
@@ -113,7 +113,7 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
       CONTENT_SETTING_DEFAULT);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
@@ -122,7 +122,7 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
@@ -131,23 +131,22 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
       CONTENT_SETTING_ALLOW);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_POPUPS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_POPUPS, ""));
+  EXPECT_EQ(CONTENT_SETTING_ASK,
+            host_content_settings_map->GetContentSetting(
+                host, host, CONTENT_SETTINGS_TYPE_GEOLOCATION, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_GEOLOCATION, std::string()));
-  EXPECT_EQ(
-      CONTENT_SETTING_ASK,
-      host_content_settings_map->GetContentSetting(
-          host, host, CONTENT_SETTINGS_TYPE_NOTIFICATIONS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_NOTIFICATIONS, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_FULLSCREEN, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_FULLSCREEN, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_MOUSELOCK, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_MOUSELOCK, ""));
 
   // Check returning all hosts for a setting.
   ContentSettingsPattern pattern2 =
@@ -165,16 +164,18 @@ TEST_F(HostContentSettingsMapTest, IndividualSettings) {
       std::string(),
       CONTENT_SETTING_BLOCK);
   ContentSettingsForOneType host_settings;
-  host_content_settings_map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_IMAGES, std::string(), &host_settings);
+  host_content_settings_map->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_IMAGES,
+                                                   "",
+                                                   &host_settings);
   // |host_settings| contains the default setting and an exception.
   EXPECT_EQ(2U, host_settings.size());
   host_content_settings_map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_PLUGINS, std::string(), &host_settings);
+      CONTENT_SETTINGS_TYPE_PLUGINS, "", &host_settings);
   // |host_settings| contains the default setting and 2 exceptions.
   EXPECT_EQ(3U, host_settings.size());
-  host_content_settings_map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_POPUPS, std::string(), &host_settings);
+  host_content_settings_map->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_POPUPS,
+                                                   "",
+                                                   &host_settings);
   // |host_settings| contains only the default setting.
   EXPECT_EQ(1U, host_settings.size());
 }
@@ -216,12 +217,13 @@ TEST_F(HostContentSettingsMapTest, Clear) {
   host_content_settings_map->ClearSettingsForOneType(
       CONTENT_SETTINGS_TYPE_IMAGES);
   ContentSettingsForOneType host_settings;
-  host_content_settings_map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_IMAGES, std::string(), &host_settings);
+  host_content_settings_map->GetSettingsForOneType(CONTENT_SETTINGS_TYPE_IMAGES,
+                                                   "",
+                                                   &host_settings);
   // |host_settings| contains only the default setting.
   EXPECT_EQ(1U, host_settings.size());
   host_content_settings_map->GetSettingsForOneType(
-      CONTENT_SETTINGS_TYPE_PLUGINS, std::string(), &host_settings);
+      CONTENT_SETTINGS_TYPE_PLUGINS, "", &host_settings);
   // |host_settings| contains the default setting and an exception.
   EXPECT_EQ(2U, host_settings.size());
 }
@@ -240,7 +242,7 @@ TEST_F(HostContentSettingsMapTest, Patterns) {
        ContentSettingsPattern::FromString("example.org");
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   host_content_settings_map->SetContentSetting(
       pattern1,
       ContentSettingsPattern::Wildcard(),
@@ -249,13 +251,13 @@ TEST_F(HostContentSettingsMapTest, Patterns) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host1, host1, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host2, host2, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host2, host2, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   host_content_settings_map->SetContentSetting(
       pattern2,
       ContentSettingsPattern::Wildcard(),
@@ -264,7 +266,7 @@ TEST_F(HostContentSettingsMapTest, Patterns) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host3, host3, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 }
 
 TEST_F(HostContentSettingsMapTest, Observer) {
@@ -325,7 +327,7 @@ TEST_F(HostContentSettingsMapTest, ObserveDefaultPref) {
       CONTENT_SETTINGS_TYPE_IMAGES, CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Make a copy of the pref's new value so we can reset it later.
   scoped_ptr<Value> new_value(prefs->FindPreference(
@@ -335,13 +337,13 @@ TEST_F(HostContentSettingsMapTest, ObserveDefaultPref) {
   prefs->Set(prefs::kDefaultContentSettings, *default_value);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Reseting the pref to its previous value should update the cache.
   prefs->Set(prefs::kDefaultContentSettings, *new_value);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 }
 
 TEST_F(HostContentSettingsMapTest, ObserveExceptionPref) {
@@ -361,7 +363,7 @@ TEST_F(HostContentSettingsMapTest, ObserveExceptionPref) {
 
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   host_content_settings_map->SetContentSetting(
       pattern,
@@ -371,7 +373,7 @@ TEST_F(HostContentSettingsMapTest, ObserveExceptionPref) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Make a copy of the pref's new value so we can reset it later.
   scoped_ptr<Value> new_value(prefs->FindPreference(
@@ -381,13 +383,13 @@ TEST_F(HostContentSettingsMapTest, ObserveExceptionPref) {
   prefs->Set(prefs::kContentSettingsPatternPairs, *default_value);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Reseting the pref to its previous value should update the cache.
   prefs->Set(prefs::kContentSettingsPatternPairs, *new_value);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 }
 
 TEST_F(HostContentSettingsMapTest, HostTrimEndingDotCheck) {
@@ -411,26 +413,26 @@ TEST_F(HostContentSettingsMapTest, HostTrimEndingDotCheck) {
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
-  EXPECT_EQ(
-      CONTENT_SETTING_ALLOW,
-      host_content_settings_map->GetContentSetting(host_ending_with_dot,
-                                                   host_ending_with_dot,
-                                                   CONTENT_SETTINGS_TYPE_IMAGES,
-                                                   std::string()));
+  EXPECT_EQ(CONTENT_SETTING_ALLOW,
+            host_content_settings_map->GetContentSetting(
+                host_ending_with_dot,
+                host_ending_with_dot,
+                CONTENT_SETTINGS_TYPE_IMAGES,
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
-  EXPECT_EQ(
-      CONTENT_SETTING_BLOCK,
-      host_content_settings_map->GetContentSetting(host_ending_with_dot,
-                                                   host_ending_with_dot,
-                                                   CONTENT_SETTINGS_TYPE_IMAGES,
-                                                   std::string()));
+  EXPECT_EQ(CONTENT_SETTING_BLOCK,
+            host_content_settings_map->GetContentSetting(
+                host_ending_with_dot,
+                host_ending_with_dot,
+                CONTENT_SETTINGS_TYPE_IMAGES,
+                ""));
 
   EXPECT_TRUE(cookie_settings->IsSettingCookieAllowed(
       host_ending_with_dot, host_ending_with_dot));
@@ -438,7 +440,7 @@ TEST_F(HostContentSettingsMapTest, HostTrimEndingDotCheck) {
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_COOKIES,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
   EXPECT_TRUE(cookie_settings->IsSettingCookieAllowed(
       host_ending_with_dot, host_ending_with_dot));
@@ -446,7 +448,7 @@ TEST_F(HostContentSettingsMapTest, HostTrimEndingDotCheck) {
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_COOKIES,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
   EXPECT_FALSE(cookie_settings->IsSettingCookieAllowed(
       host_ending_with_dot, host_ending_with_dot));
@@ -456,93 +458,93 @@ TEST_F(HostContentSettingsMapTest, HostTrimEndingDotCheck) {
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-                std::string()));
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-                std::string()));
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-                std::string()));
+                ""));
 
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_PLUGINS,
-                std::string()));
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_PLUGINS,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_PLUGINS,
-                std::string()));
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_PLUGINS,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
                 host_ending_with_dot,
                 host_ending_with_dot,
                 CONTENT_SETTINGS_TYPE_PLUGINS,
-                std::string()));
+                ""));
 
-  EXPECT_EQ(
-      CONTENT_SETTING_BLOCK,
-      host_content_settings_map->GetContentSetting(host_ending_with_dot,
-                                                   host_ending_with_dot,
-                                                   CONTENT_SETTINGS_TYPE_POPUPS,
-                                                   std::string()));
+  EXPECT_EQ(CONTENT_SETTING_BLOCK,
+            host_content_settings_map->GetContentSetting(
+                host_ending_with_dot,
+                host_ending_with_dot,
+                CONTENT_SETTINGS_TYPE_POPUPS,
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_POPUPS,
-      std::string(),
+      "",
       CONTENT_SETTING_DEFAULT);
-  EXPECT_EQ(
-      CONTENT_SETTING_BLOCK,
-      host_content_settings_map->GetContentSetting(host_ending_with_dot,
-                                                   host_ending_with_dot,
-                                                   CONTENT_SETTINGS_TYPE_POPUPS,
-                                                   std::string()));
+  EXPECT_EQ(CONTENT_SETTING_BLOCK,
+            host_content_settings_map->GetContentSetting(
+                host_ending_with_dot,
+                host_ending_with_dot,
+                CONTENT_SETTINGS_TYPE_POPUPS,
+                ""));
   host_content_settings_map->SetContentSetting(
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_POPUPS,
-      std::string(),
+      "",
       CONTENT_SETTING_ALLOW);
-  EXPECT_EQ(
-      CONTENT_SETTING_ALLOW,
-      host_content_settings_map->GetContentSetting(host_ending_with_dot,
-                                                   host_ending_with_dot,
-                                                   CONTENT_SETTINGS_TYPE_POPUPS,
-                                                   std::string()));
+  EXPECT_EQ(CONTENT_SETTING_ALLOW,
+            host_content_settings_map->GetContentSetting(
+                host_ending_with_dot,
+                host_ending_with_dot,
+                CONTENT_SETTINGS_TYPE_POPUPS,
+                ""));
 }
 
 TEST_F(HostContentSettingsMapTest, NestedSettings) {
@@ -562,53 +564,52 @@ TEST_F(HostContentSettingsMapTest, NestedSettings) {
       pattern1,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
 
   host_content_settings_map->SetContentSetting(
       pattern2,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_COOKIES,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
 
   host_content_settings_map->SetContentSetting(
       pattern3,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_PLUGINS,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
   host_content_settings_map->SetDefaultContentSetting(
       CONTENT_SETTINGS_TYPE_JAVASCRIPT, CONTENT_SETTING_BLOCK);
 
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_COOKIES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_COOKIES, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_POPUPS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_POPUPS, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_GEOLOCATION, std::string()));
-  EXPECT_EQ(
-      CONTENT_SETTING_ASK,
-      host_content_settings_map->GetContentSetting(
-          host, host, CONTENT_SETTINGS_TYPE_NOTIFICATIONS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_GEOLOCATION, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_FULLSCREEN, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_NOTIFICATIONS, ""));
   EXPECT_EQ(CONTENT_SETTING_ASK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_MOUSELOCK, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_FULLSCREEN, ""));
+  EXPECT_EQ(CONTENT_SETTING_ASK,
+            host_content_settings_map->GetContentSetting(
+                host, host, CONTENT_SETTINGS_TYPE_MOUSELOCK, ""));
 }
 
 TEST_F(HostContentSettingsMapTest, OffTheRecord) {
@@ -625,10 +626,10 @@ TEST_F(HostContentSettingsMapTest, OffTheRecord) {
 
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             otr_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Changing content settings on the main map should also affect the
   // incognito map.
@@ -636,28 +637,27 @@ TEST_F(HostContentSettingsMapTest, OffTheRecord) {
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_IMAGES,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             otr_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   // Changing content settings on the incognito map should NOT affect the
   // main map.
-  otr_map->SetContentSetting(pattern,
-                             ContentSettingsPattern::Wildcard(),
-                             CONTENT_SETTINGS_TYPE_IMAGES,
-                             std::string(),
-                             CONTENT_SETTING_ALLOW);
+  otr_map->SetContentSetting(
+      pattern,
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_IMAGES, "", CONTENT_SETTING_ALLOW);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             otr_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 
   otr_map->ShutdownOnUIThread();
 }
@@ -738,7 +738,7 @@ TEST_F(HostContentSettingsMapTest, ResourceIdentifier) {
           CONTENT_SETTINGS_TYPE_PLUGINS, NULL);
   EXPECT_EQ(default_plugin_setting,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_PLUGINS, ""));
 
   // If no resource-specific content settings are defined, the setting should be
   // DEFAULT.
@@ -865,7 +865,7 @@ TEST_F(HostContentSettingsMapTest,
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-      std::string(),
+      "",
       CONTENT_SETTING_BLOCK);
 
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
@@ -875,14 +875,14 @@ TEST_F(HostContentSettingsMapTest,
   GURL host("http://example.com/");
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
 
   // Set managed-default-content-setting for content-settings-type JavaScript.
   prefs->SetManagedPref(prefs::kManagedDefaultJavaScriptSetting,
                         Value::CreateIntegerValue(CONTENT_SETTING_ALLOW));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
 }
 
 // Managed default content setting should have higher priority
@@ -906,7 +906,7 @@ TEST_F(HostContentSettingsMapTest,
       pattern,
       ContentSettingsPattern::Wildcard(),
       CONTENT_SETTINGS_TYPE_JAVASCRIPT,
-      std::string(),
+      "",
       CONTENT_SETTING_ALLOW);
 
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
@@ -915,20 +915,20 @@ TEST_F(HostContentSettingsMapTest,
   GURL host("http://example.com/");
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
 
   // Set managed-default-content-settings-preferences.
   prefs->SetManagedPref(prefs::kManagedDefaultJavaScriptSetting,
                         Value::CreateIntegerValue(CONTENT_SETTING_BLOCK));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
 
   // Remove managed-default-content-settings-preferences.
   prefs->RemoveManagedPref(prefs::kManagedDefaultJavaScriptSetting);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_JAVASCRIPT, ""));
 }
 
 // If a default-content-setting is set to managed setting, the user defined
@@ -1004,10 +1004,10 @@ TEST_F(HostContentSettingsMapTest, GetContentSetting) {
       CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             host_content_settings_map->GetContentSetting(
-                host, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             host_content_settings_map->GetContentSetting(
-                embedder, host, CONTENT_SETTINGS_TYPE_IMAGES, std::string()));
+                embedder, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
 }
 
 TEST_F(HostContentSettingsMapTest, ShouldAllowAllContent) {
diff --git a/chrome/browser/content_settings/mock_settings_observer.cc b/chrome/browser/content_settings/mock_settings_observer.cc
index c8de7fa..a281a1d 100644
--- a/chrome/browser/content_settings/mock_settings_observer.cc
+++ b/chrome/browser/content_settings/mock_settings_observer.cc
@@ -35,5 +35,5 @@ void MockSettingsObserver::Observe(
   // This checks that calling a Get function from an observer doesn't
   // deadlock.
   GURL url("http://random-hostname.com/");
-  map->GetContentSetting(url, url, CONTENT_SETTINGS_TYPE_IMAGES, std::string());
+  map->GetContentSetting(url, url, CONTENT_SETTINGS_TYPE_IMAGES, "");
 }