Stop using the MEDIASTREAM content setting.

components/content_settings/core/browser/content_settings_default_provider.cc

Index: components/content_settings/core/browser/content_settings_default_provider.cc
diff --git a/components/content_settings/core/browser/content_settings_default_provider.cc b/components/content_settings/core/browser/content_settings_default_provider.cc
index bd0f474d9dc42205340c8cd696214e68598e4cf4..0f7d98f1694eceed0b4c13aedc89ce390a1634da 100644
--- a/components/content_settings/core/browser/content_settings_default_provider.cc
+++ b/components/content_settings/core/browser/content_settings_default_provider.cc
@@ -99,6 +99,10 @@ void DefaultProvider::RegisterProfilePrefs(
       prefs::kDefaultContentSettings,
       default_content_settings,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterBooleanPref(
+      prefs::kMigratedDefaultMediaStreamSetting,
+      false,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 DefaultProvider::DefaultProvider(PrefService* prefs, bool incognito)
@@ -110,6 +114,11 @@ DefaultProvider::DefaultProvider(PrefService* prefs, bool incognito)
   // Read global defaults.
   ReadDefaultSettings(true);
 
+  // Migrate the obsolete media stream default setting into the new microphone
+  // and camera settings.
+  if (!is_incognito_)
+    MigrateObsoleteMediaContentSetting();
+
   UMA_HISTOGRAM_ENUMERATION(
       "ContentSettings.DefaultCookiesSetting",
       ValueToContentSetting(
@@ -336,4 +345,30 @@ void DefaultProvider::GetSettingsFromDictionary(
   }
 }
 
+void DefaultProvider::MigrateObsoleteMediaContentSetting() {
+  // We only do the migration once.
+  if (prefs_->GetBoolean(prefs::kMigratedDefaultMediaStreamSetting))
+    return;
+
+  int old_value;
+  default_settings_[CONTENT_SETTINGS_TYPE_MEDIASTREAM]->GetAsInteger(

[markusheintz_, 2015/03/06 16:05:33]

Do the default_settings_ contain values for settings that were never changed by
the user?

[msramek, 2015/03/06 17:47:33]

Hm, you're right. I was under incorrect impression that all values would be set.
It looks like they don't have to be. This can be handled the same way as on
lines 122-176 by using ValueToContentSetting, which interprets NULL as
CONTENT_SETTING_DEFAULT.

+      &old_value);
+
+  SetWebsiteSetting(
+      ContentSettingsPattern::Wildcard(),
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_MEDIASTREAM_MIC,
+      std::string(),
+      new base::FundamentalValue(old_value));
+
+  SetWebsiteSetting(
+      ContentSettingsPattern::Wildcard(),
+      ContentSettingsPattern::Wildcard(),
+      CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA,
+      std::string(),
+      new base::FundamentalValue(old_value));
+
+  prefs_->SetBoolean(prefs::kMigratedDefaultMediaStreamSetting, true);
+}
+
 }  // namespace content_settings