Apps on NTP should be in order of installation

chrome/browser/extensions/pending_extension_manager.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_PENDING_EXTENSION_MANAGER_H_
 #define CHROME_BROWSER_EXTENSIONS_PENDING_EXTENSION_MANAGER_H_
 #pragma once
 
-#include <map>
+#include <list>
 #include <string>
+#include <utility>
 
 #include "chrome/browser/extensions/pending_extension_info.h"
 #include "chrome/common/extensions/extension.h"
 
 class ExtensionServiceInterface;
 class GURL;
 class PendingExtensionManager;
 class Version;
 
 namespace extensions {
@@ skipping 15 matching lines @@
   // |service| is a reference to the ExtensionService whose pending
   // extensions we are managing. The service creates an instance of
   // this class on construction, and destroys it on destruction.
   // The service remains valid over the entire lifetime of this class.
   explicit PendingExtensionManager(const ExtensionServiceInterface& service);
   ~PendingExtensionManager();
 
   // TODO(skerner): Many of these methods can be private once code in
   // ExtensionService is moved into methods of this class.
 
-  // Remove |id| from the set of pending extensions.
-  void Remove(const std::string& id);
+  // Remove extension with id |id| from the set of pending extensions. Returns
+  // true if such an extension was found and removed, false otherwise.
+  bool Remove(const std::string& id);
 
-  // Get the  information for a pending extension.  Returns true and sets
-  // |out_pending_extension_info| if there is a pending extension with id
-  // |id|.  Returns false otherwise.
-  bool GetById(const std::string& id,
-               PendingExtensionInfo* out_pending_extension_info) const;
+  // Get the  information for a pending extension.  Returns a pointer to the
+  // pending extension with id |id|, or NULL if there is no such extension.
+  const PendingExtensionInfo* GetById(const std::string& id) const;
 
   // Is |id| in the set of pending extensions?
   bool IsIdPending(const std::string& id) const;
 
   // Adds an extension in a pending state; the extension with the
   // given info will be installed on the next auto-update cycle.
   // Return true if the extension was added.  Will return false
   // if the extension is pending from another source which overrides
   // sync installs (such as a policy extension) or if the extension
   // is already installed.
@@ skipping 13 matching lines @@
                                 extensions::Extension::Location location);
 
   // Add a pending extension record for an external CRX file.
   // Return true if the CRX should be installed, false if an existing
   // pending record overrides it.
   bool AddFromExternalFile(
       const std::string& id,
       extensions::Extension::Location location,
       const Version& version);
 
-  // Get the set of pending IDs that should be installed from an update URL.
+  // Get the list of pending IDs that should be installed from an update URL.
   // Pending extensions that will be installed from local files will not be
   // included in the set.
   void GetPendingIdsForUpdateCheck(
-      std::set<std::string>* out_ids_for_update_check) const;
+      std::list<std::string>* out_ids_for_update_check) const;
 
  private:
-  typedef std::map<std::string, PendingExtensionInfo> PendingExtensionMap;
+  typedef std::list<PendingExtensionInfo> PendingExtensionList;
 
   // Assumes an extension with id |id| is not already installed.
   // Return true if the extension was added.
   bool AddExtensionImpl(
       const std::string& id,
       const GURL& update_url,
       const Version& version,
       PendingExtensionInfo::ShouldAllowInstallPredicate should_allow_install,
       bool is_from_sync,
       bool install_silently,
       extensions::Extension::Location install_source);
 
   // Add a pending extension record directly.  Used for unit tests that need
   // to set an inital state. Use friendship to allow the tests to call this
   // method.
-  void AddForTesting(const std::string& id,
-                     const PendingExtensionInfo& pending_etension_info);
+  void AddForTesting(const PendingExtensionInfo& pending_extension_info);
 
   // Reference to the extension service whose pending extensions this class is
   // managing.  Because this class is a member of |service_|, it is created
   // and destroyed with |service_|. We only use methods from the interface
   // ExtensionServiceInterface.
   const ExtensionServiceInterface& service_;
 
-  // A map from extension id to the pending extension info for that extension.
-  PendingExtensionMap pending_extension_map_;
+  PendingExtensionList pending_extension_list_;
 
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            UpdatePendingExtensionAlreadyInstalled);
   friend class extensions::ExtensionUpdaterTest;
   friend void extensions::SetupPendingExtensionManagerForTest(
       int count, const GURL& update_url,
       PendingExtensionManager* pending_extension_manager);
 
   DISALLOW_COPY_AND_ASSIGN(PendingExtensionManager);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_PENDING_EXTENSION_MANAGER_H_