Add update url controlled extension management settings

chrome/browser/extensions/extension_management_internal.h

Index: chrome/browser/extensions/extension_management_internal.h
diff --git a/chrome/browser/extensions/extension_management_internal.h b/chrome/browser/extensions/extension_management_internal.h
index 0b3eaffb3ab9f7523f77576c754a6157dfacf19a..944f710a3da9a4087e60823071eaeb649d24312b 100644
--- a/chrome/browser/extensions/extension_management_internal.h
+++ b/chrome/browser/extensions/extension_management_internal.h
@@ -26,10 +26,22 @@ namespace internal {
 // extensions. Settings can be applied to an individual extension identified
 // by an ID, a group of extensions with specific |update_url| or all
 // extensions at once.
+// The settings applied to all extensions are the default settings and can be
+// overridden by per-extension or per-update-url settings.
+// There are multiple fields in this class. Unspecified fields in per-extension
+// and per-update-url settings will take value from default settings (or merge
+// from that, see per-field comments below for details). Unspecified fields in
+// default extensions will take the default fall back value instead.
+// Since update URL is not directly associated to extension ID, per-extension
+// and per-update-url settings might be enforced at the same time, see per-field
+// comments below for details.
 struct IndividualSettings {
   enum ParsingScope {
     // Parses the default settings.
     SCOPE_DEFAULT = 0,
+    // Parses the settings for extensions with specified update URL in its
+    // manifest.
+    SCOPE_UPDATE_URL,
     // Parses the settings for an extension with specified extension ID.
     SCOPE_INDIVIDUAL,
   };
@@ -39,12 +51,12 @@ struct IndividualSettings {
 
   void Reset();
 
-  // Parses the individual settings. |dict| is the a sub-dictionary in extension
+  // Parses the individual settings. |dict| is a sub-dictionary in extension
   // management preference and |scope| represents the applicable range of the
   // settings, a single extension, a group of extensions or default settings.
   // Note that in case of parsing errors, |this| will NOT be left untouched.
-  // This method is required to be called in order of ParsingScope, i.e. first
-  // SCOPE_DEFAULT, then SCOPE_INDIVIDUAL.
+  // This method is required to be called for SCOPE_DEFAULT first, then
+  // for SCOPE_INDIVIDUAL and SCOPE_UPDATE_URL.
   bool Parse(const base::DictionaryValue* dict, ParsingScope scope);
 
   // Extension installation mode. Setting this to INSTALLATION_FORCED or
@@ -53,20 +65,25 @@ struct IndividualSettings {
   // be specified, containing the update URL for this extension.
   // Note that |update_url| will be ignored for INSTALLATION_ALLOWED and
   // INSTALLATION_BLOCKED installation mode.
-  // These settings will override the default settings, and unspecified
-  // settings will take value from default settings.
+  // This setting will override the default settings, and unspecified
+  // setting will take value from default settings.
+  // In case this setting is specified in both per-extensions and
+  // per-update-url settings, per-extension settings will override
+  // per-update-url settings.
   ExtensionManagement::InstallationMode installation_mode;
   std::string update_url;
 
-  // Permissions settings for extensions. These settings won't grant permissions
-  // to extensions automatically. Instead, these settings will provide a list of
+  // Permissions block list for extensions. This setting won't grant permissions
+  // to extensions automatically. Instead, this setting will provide a list of
   // blocked permissions for each extension. That is, if an extension requires a
   // permission which has been blacklisted, this extension will not be allowed
   // to load. And if it contains a blocked permission as optional requirement,
   // it will be allowed to load (of course, with permission granted from user if
-  // necessary), but conflicting permissions will be dropped. These settings
-  // will merge from the default settings, and unspecified settings will take
-  // value from default settings.
+  // necessary), but conflicting permissions will be dropped. This setting will
+  // merge from the default settings, and unspecified settings will take value
+  // from default settings.
+  // In case this setting is specified in both per-extensions and per-update-url
+  // settings, both settings will be enforced.
   APIPermissionSet blocked_permissions;
 
  private: