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

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
===================================================================
--- chrome/browser/extensions/extension_service.h	(revision 138227)
+++ chrome/browser/extensions/extension_service.h	(working copy)
@@ -20,6 +20,7 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/property_bag.h"
+#include "base/string16.h"
 #include "base/time.h"
 #include "base/tuple.h"
 #include "chrome/browser/extensions/app_shortcut_manager.h"
@@ -34,6 +35,7 @@
 #include "chrome/browser/extensions/extension_warning_set.h"
 #include "chrome/browser/extensions/extensions_quota_service.h"
 #include "chrome/browser/extensions/external_extension_provider_interface.h"
+#include "chrome/browser/extensions/management_policy.h"
 #include "chrome/browser/extensions/pending_extension_manager.h"
 #include "chrome/browser/extensions/process_map.h"
 #include "chrome/browser/extensions/sandboxed_extension_unpacker.h"
@@ -141,6 +143,7 @@
 // Manages installed and running Chromium extensions.
 class ExtensionService
     : public ExtensionServiceInterface,
+      public extensions::ManagementPolicy::Provider,
       public ExternalExtensionProviderInterface::VisitorInterface,
       public base::SupportsWeakPtr<ExtensionService>,
       public content::NotificationObserver {
@@ -329,13 +332,22 @@
   // to ExtensionPrefs some other way.
   virtual bool UninstallExtension(std::string extension_id,
                                   bool external_uninstall,
-                                  std::string* error);
+                                  string16* error);
 
   virtual bool IsExtensionEnabled(
       const std::string& extension_id) const OVERRIDE;
   virtual bool IsExternalExtensionUninstalled(
       const std::string& extension_id) const OVERRIDE;
 
+  // ManagementPolicy::Provider
+  // The ExtensionService exposes any restrictions imposed by an individual

[Aaron Boodman, 2012/05/22 15:56:11]

This comment doesn't seem correct compared to the code.

+  // extension.
+  virtual std::string PolicyProviderName() const OVERRIDE;
+  virtual bool UserMayModifyStatus(const extensions::Extension* extension,
+                                   string16* error) const OVERRIDE;
+  virtual bool MustRemainEnabled(const extensions::Extension* extension,
+                                 string16* error) const OVERRIDE;
+
   // Enables the extension.  If the extension is already enabled, does
   // nothing.
   virtual void EnableExtension(const std::string& extension_id);
@@ -410,7 +422,7 @@
       const std::vector<std::string>& blacklist) OVERRIDE;
 
   // Go through each extension and unload those that the network admin has
-  // put on the blacklist (not to be confused with the Google managed blacklist
+  // put on the blacklist (not to be confused with the Google-managed blacklist)
   // set of extensions.
   virtual void CheckAdminBlacklist() OVERRIDE;
 
@@ -664,6 +676,12 @@
       bool include_disabled,
       bool include_terminated) const;
 
+  // Internal implementation for ManagementPolicy::Delegate methods.
+  // Returns |modifiable_value| if the extension can be modified.
+  bool ManagementPolicyImpl(const extensions::Extension* extension,
+                            string16* error,
+                            bool modifiable_value) const;
+
   // Adds the given extension to the list of terminated extensions if
   // it is not already there and unloads it.
   void TrackTerminatedExtension(const extensions::Extension* extension);