Add a group policy controlling which sites can install extensions.

chrome/browser/policy/configuration_policy_handler.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_POLICY_CONFIGURATION_POLICY_HANDLER_H_
 #define CHROME_BROWSER_POLICY_CONFIGURATION_POLICY_HANDLER_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 110 matching lines @@
                        PolicyErrorMap* errors,
                        const base::ListValue** extension_ids);
 
  private:
   const char* pref_path_;
   bool allow_wildcards_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionListPolicyHandler);
 };
 
+// Implements additional checks for policies that are lists of extension
+// URLPatterns.
+class ExtensionURLPatternListPolicyHandler : public TypeCheckingPolicyHandler {
+ public:
+  ExtensionURLPatternListPolicyHandler(const char* policy_name,
+                                       const char* pref_path);
+  virtual ~ExtensionURLPatternListPolicyHandler();
+
+  // ConfigurationPolicyHandler methods:
+  virtual bool CheckPolicySettings(const PolicyMap& policies,
+                                   PolicyErrorMap* errors) OVERRIDE;
+  virtual void ApplyPolicySettings(const PolicyMap& policies,
+                                   PrefValueMap* prefs) OVERRIDE;
+
+ private:
+  const char* pref_path_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionURLPatternListPolicyHandler);
+};
+
 // ConfigurationPolicyHandler for the SyncDisabled policy.
 class SyncPolicyHandler : public TypeCheckingPolicyHandler {
  public:
   SyncPolicyHandler();
   virtual ~SyncPolicyHandler();
 
   // ConfigurationPolicyHandler methods:
   virtual void ApplyPolicySettings(const PolicyMap& policies,
                                    PrefValueMap* prefs) OVERRIDE;
 
@@ skipping 209 matching lines @@
  private:
   void ApplyPolicySettingsFromHomePage(const PolicyMap& policies,
                                        PrefValueMap* prefs);
 
   DISALLOW_COPY_AND_ASSIGN(RestoreOnStartupPolicyHandler);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_CONFIGURATION_POLICY_HANDLER_H_