Don't ping for extension blacklist when no extensions are installed....

chrome/browser/extensions/extensions_service.h

 // Copyright (c) 2009 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_EXTENSIONS_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSIONS_SERVICE_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 33 matching lines @@
 // ExtensionUpdater has on ExtensionsService. This allows easy mocking.
 class ExtensionUpdateService {
  public:
   virtual ~ExtensionUpdateService() {}
   virtual const ExtensionList* extensions() const = 0;
   virtual void UpdateExtension(const std::string& id, const FilePath& path) = 0;
   virtual Extension* GetExtensionById(const std::string& id,
                                       bool include_disabled) = 0;
   virtual void UpdateExtensionBlacklist(
     const std::vector<std::string>& blacklist) = 0;
+  virtual bool HasInstalledExtensions() = 0;
 };
 
 // Manages installed and running Chromium extensions.
 class ExtensionsService
     : public base::RefCountedThreadSafe<ExtensionsService,
                                         ChromeThread::DeleteOnUIThread>,
       public BlacklistPathProvider,
       public ExtensionUpdateService,
       public NotificationObserver {
  public:
@@ skipping 17 matching lines @@
                     PrefService* prefs,
                     const FilePath& install_directory,
                     bool autoupdate_enabled);
 
   // Gets the list of currently installed extensions.
   virtual const ExtensionList* extensions() const { return &extensions_; }
   virtual const ExtensionList* disabled_extensions() const {
     return &disabled_extensions_;
   }
 
+  // Returns true if any extensions are installed.
+  virtual bool HasInstalledExtensions() {
+    return !(extensions_.empty() && disabled_extensions_.empty());
+  }
+
   const FilePath& install_directory() const { return install_directory_; }
 
   // Initialize and start all installed extensions.
   void Init();
 
   // Look up an extension by ID.
   Extension* GetExtensionById(const std::string& id, bool include_disabled) {
     return GetExtensionByIdInternal(id, true, include_disabled);
   }
 
@@ skipping 285 matching lines @@
 
   // A map of all external extension providers.
   typedef std::map<Extension::Location,
                    linked_ptr<ExternalExtensionProvider> > ProviderMap;
   ProviderMap external_extension_providers_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionsServiceBackend);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSIONS_SERVICE_H_