Refactor the various ways to control what users can do to extensions.

chrome/browser/extensions/extension_prefs.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_PREFS_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_PREFS_H_
 #pragma once
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/memory/linked_ptr.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/api/content_settings/content_settings_store.h"
 #include "chrome/browser/extensions/extension_prefs_scope.h"
 #include "chrome/browser/extensions/extension_scoped_prefs.h"
+#include "chrome/browser/extensions/management_policy.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/string_ordinal.h"
 
 class ExtensionPrefValueMap;
 class ExtensionSorting;
 class PrefService;
 class URLPatternSet;
 
 namespace extensions {
 struct AlarmPref;
 struct ExtensionOmniboxSuggestion;
 }
 
 // Class for managing global and per-extension preferences.
 //
 // This class distinguishes the following kinds of preferences:
 // - global preferences:
 //       internal state for the extension system in general, not associated
 //       with an individual extension, such as lastUpdateTime.
 // - per-extension preferences:
 //       meta-preferences describing properties of the extension like
 //       installation time, whether the extension is enabled, etc.
 // - extension controlled preferences:
 //       browser preferences that an extension controls. For example, an
 //       extension could use the proxy API to specify the browser's proxy
 //       preference. Extension-controlled preferences are stored in
 //       PrefValueStore::extension_prefs(), which this class populates and
 //       maintains as the underlying extensions change.
 class ExtensionPrefs : public extensions::ContentSettingsStore::Observer,
+                       public extensions::ManagementPolicy::Provider,
                        public ExtensionScopedPrefs {
  public:
   // Key name for a preference that keeps track of per-extension settings. This
   // is a dictionary object read from the Preferences file, keyed off of
   // extension ids.
   static const char kExtensionsPref[];
 
   typedef std::vector<linked_ptr<extensions::ExtensionInfo> > ExtensionsInfo;
 
   // Vector containing identifiers for preferences.
@@ skipping 141 matching lines @@
 
   // The oauth client id used for app notification setup, if any.
   std::string GetAppNotificationClientId(const std::string& extension_id) const;
   void SetAppNotificationClientId(const std::string& extension_id,
                                   const std::string& oauth_client_id);
 
   // Whether app notifications are disabled for the given app.
   bool IsAppNotificationDisabled(const std::string& extension_id) const;
   void SetAppNotificationDisabled(const std::string& extension_id, bool value);
 
-  // Is the extension with |extension_id| allowed by policy (checking both
-  // whitelist and blacklist).
-  bool IsExtensionAllowedByPolicy(const std::string& extension_id,
-      extensions::Extension::Location location) const;
+  // ManagementPolicy::Provider

[Aaron Boodman, 2012/05/29 03:03:08]

I would really prefer this be a separate helper class.

The admin forcelist policy implementation is really a totally different thing
than ExtensionPrefs. Mixing them together ends up requiring these comments to
explain what could be clear from a different factoring.

So add admin_policy.h/cc or whatever and ExtensionPrefs::GetAdminPolicy().

+  virtual std::string GetPolicyProviderName() const OVERRIDE;
+  // Returns true if the extension is allowed by admin policy white- and
+  // blacklists.
+  virtual bool UserMayLoad(const extensions::Extension* extension,
+                           string16* error) const OVERRIDE;
+  // Returns false if the extension is required to remain running, as determined
+  // by Extension::IsRequired(). In practice this enforces the admin policy
+  // forcelist.
+  virtual bool UserMayModifySettings(const extensions::Extension* extension,
+                                     string16* error) const OVERRIDE;
+  // Returns true if the extension is required to remain running, as determined
+  // by Extension::IsRequired(). In practice this enforces the admin policy
+  // forcelist.
+  virtual bool MustRemainEnabled(const extensions::Extension* extension,
+                                 string16* error) const OVERRIDE;
 
   // Checks if extensions are blacklisted by default, by policy. When true, this
   // means that even extensions without an ID should be blacklisted (e.g.
   // from the command line, or when loaded as an unpacked extension).
   // IsExtensionAllowedByPolicy() also takes this into account, and should be
   // used instead when the extension ID is known.
   bool ExtensionsBlacklistedByDefault() const;
 
   // Returns the last value set via SetLastPingDay. If there isn't such a
   // pref, the returned Time will return true for is_null().
@@ skipping 278 matching lines @@
   // exist.
   const base::DictionaryValue* GetExtensionPref(const std::string& id) const;
 
   // Returns the dictionary of preferences controlled by the specified extension
   // or creates a new one. All entries in the dictionary contain non-expanded
   // paths.
   const base::DictionaryValue* GetExtensionControlledPrefs(
       const std::string& id,
       bool incognito) const;
 
+  // Internal implementation for certain ManagementPolicy::Delegate methods.
+  // Returns |modifiable_value| if the extension can be modified.
+  bool ManagementPolicyImpl(const extensions::Extension* extension,
+                            string16* error,
+                            bool modifiable_value) const;
+
   // Checks if kPrefBlacklist is set to true in the DictionaryValue.
   // Return false if the value is false or kPrefBlacklist does not exist.
   // This is used to decide if an extension is blacklisted.
   static bool IsBlacklistBitSet(base::DictionaryValue* ext);
 
   // Fix missing preference entries in the extensions that are were introduced
   // in a later Chrome version.
   void FixMissingPrefs(const ExtensionIdSet& extension_ids);
 
   // Installs the persistent extension preferences into |prefs_|'s extension
@@ skipping 20 matching lines @@
   // Contains all the logic for handling the order for various extension
   // properties.
   scoped_ptr<ExtensionSorting> extension_sorting_;
 
   scoped_refptr<extensions::ContentSettingsStore> content_settings_store_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionPrefs);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PREFS_H_