Disabled external_extensions.json and chrome://extensions in Guest mode.

chrome/browser/extensions/extensions_service.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/extensions/extensions_service.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
@@ skipping 162 matching lines @@
 }
 
 }  // namespace
 
 // Implements IO for the ExtensionsService.
 
 class ExtensionsServiceBackend
     : public base::RefCountedThreadSafe<ExtensionsServiceBackend>,
       public ExternalExtensionProvider::Visitor {
  public:
-  // |rdh| can be NULL in the case of test environment.
-  // |extension_prefs| contains a dictionary value that points to the extension
-  // preferences.
-  explicit ExtensionsServiceBackend(const FilePath& install_directory);
+  // |install_directory| is a path where to look for extensions to load.
+  // |load_external_extensions| indicates whether or not backend should load
+  // external extensions listed in JSON file and Windows registry.
+  ExtensionsServiceBackend(const FilePath& install_directory,
+                           bool load_external_extensions);
 
   // Loads a single extension from |path| where |path| is the top directory of
   // a specific extension where its manifest file lives.
   // Errors are reported through ExtensionErrorReporter. On success,
   // OnExtensionLoaded() is called.
   // TODO(erikkay): It might be useful to be able to load a packed extension
   // (presumably into memory) without installing it.
   void LoadSingleExtension(const FilePath &path,
                            scoped_refptr<ExtensionsService> frontend);
 
@@ skipping 81 matching lines @@
 
   // Set to true by OnExternalExtensionUpdateUrlFound() when an external
   // extension URL is found.  Used in CheckForExternalUpdates() to see
   // if an update check is needed to install pending extensions.
   bool external_extension_added_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionsServiceBackend);
 };
 
 ExtensionsServiceBackend::ExtensionsServiceBackend(
-    const FilePath& install_directory)
+    const FilePath& install_directory,
+    bool load_external_extensions)
         : frontend_(NULL),
           install_directory_(install_directory),
           alert_on_error_(false),
           external_extension_added_(false) {
+  if (!load_external_extensions)
+    return;
+
   // TODO(aa): This ends up doing blocking IO on the UI thread because it reads
   // pref data in the ctor and that is called on the UI thread. Would be better
   // to re-read data each time we list external extensions, anyway.
   external_extension_providers_[Extension::EXTERNAL_PREF] =
       linked_ptr<ExternalExtensionProvider>(
           new ExternalPrefExtensionProvider());
 #if defined(OS_WIN)
   external_extension_providers_[Extension::EXTERNAL_REGISTRY] =
       linked_ptr<ExternalExtensionProvider>(
           new ExternalRegistryExtensionProvider());
@@ skipping 246 matching lines @@
   if (autoupdate_enabled) {
     int update_frequency = kDefaultUpdateFrequencySeconds;
     if (command_line->HasSwitch(switches::kExtensionsUpdateFrequency)) {
       base::StringToInt(command_line->GetSwitchValueASCII(
           switches::kExtensionsUpdateFrequency),
           &update_frequency);
     }
     updater_ = new ExtensionUpdater(this, prefs, update_frequency);
   }
 
-  backend_ = new ExtensionsServiceBackend(install_directory_);
+  backend_ = new ExtensionsServiceBackend(install_directory_,
+                                          extensions_enabled_);
 
   // Use monochrome icons for Omnibox icons.
   omnibox_popup_icon_manager_.set_monochrome(true);
   omnibox_icon_manager_.set_monochrome(true);
   omnibox_icon_manager_.set_padding(gfx::Insets(0, kOmniboxIconPaddingLeft,
                                                 0, kOmniboxIconPaddingRight));
 }
 
 ExtensionsService::~ExtensionsService() {
   UnloadAllExtensions();
@@ skipping 1217 matching lines @@
     return false;
 
   for (ExtensionList::const_iterator it = extensions_.begin();
        it != extensions_.end(); ++it) {
     if ((*it)->is_app())
       return true;
   }
 
   return false;
 }