Remove //chrome dependency from ExtensionPrefs

apps/shell/browser/shell_extensions_browser_client.cc

 // Copyright 2013 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 "apps/shell/browser/shell_extensions_browser_client.h"
 
 #include "apps/common/api/generated_api.h"
 #include "apps/shell/browser/shell_app_sorting.h"
 #include "apps/shell/browser/shell_extension_system_factory.h"
 #include "apps/shell/browser/shell_extension_web_contents_observer.h"
@@ skipping 136 matching lines @@
     const extensions::Extension* extension,
     content::BrowserContext* context) const {
   return false;
 }
 
 PrefService* ShellExtensionsBrowserClient::GetPrefServiceForContext(
     BrowserContext* context) {
   return prefs_.get();
 }
 
+void ShellExtensionsBrowserClient::GetEarlyExtensionPrefsObservers(
+    content::BrowserContext* context,
+    std::vector<ExtensionPrefsObserver*>* observers) const {}
+
 bool ShellExtensionsBrowserClient::DeferLoadingBackgroundHosts(
     BrowserContext* context) const {
   return false;
 }
 
 bool ShellExtensionsBrowserClient::IsBackgroundPageAllowed(
     BrowserContext* context) const {
   return true;
 }
 
@@ skipping 34 matching lines @@
   // Generated APIs from lower-level modules.
   extensions::core_api::GeneratedFunctionRegistry::RegisterAll(registry);
   apps::api::GeneratedFunctionRegistry::RegisterAll(registry);
 
   // TODO(rockot): Remove dependency on src/chrome once we have some core APIs
   // moved out. See http://crbug.com/349042.
   extensions::api::GeneratedFunctionRegistry::RegisterAll(registry);
 }
 
 }  // namespace extensions