Introduce DeclarativeUserScriptManager.

extensions/shell/browser/shell_extension_system.h

Index: extensions/shell/browser/shell_extension_system.h
diff --git a/extensions/shell/browser/shell_extension_system.h b/extensions/shell/browser/shell_extension_system.h
index 7729d356c413287b683d64f037adf0c427ad2d0d..871a7d873de792c361e6906b998405d2778e9824 100644
--- a/extensions/shell/browser/shell_extension_system.h
+++ b/extensions/shell/browser/shell_extension_system.h
@@ -12,6 +12,7 @@
 #include "extensions/common/one_shot_event.h"
 
 class BrowserContextKeyedServiceFactory;
+class DeclarativeUserScriptManager;
 
 namespace base {
 class FilePath;
@@ -23,7 +24,6 @@ class BrowserContext;
 
 namespace extensions {
 
-class DeclarativeUserScriptMaster;
 class EventRouter;
 class InfoMap;
 class LazyBackgroundTaskQueue;
@@ -57,6 +57,7 @@ class ShellExtensionSystem : public ExtensionSystem {
   RuntimeData* runtime_data() override;
   ManagementPolicy* management_policy() override;
   SharedUserScriptMaster* shared_user_script_master() override;
+  DeclarativeUserScriptManager* declarative_user_script_manager() override;
   StateStore* state_store() override;
   StateStore* rules_store() override;
   InfoMap* info_map() override;
@@ -74,8 +75,6 @@ class ShellExtensionSystem : public ExtensionSystem {
   ContentVerifier* content_verifier() override;
   scoped_ptr<ExtensionSet> GetDependentExtensions(
       const Extension* extension) override;
-  DeclarativeUserScriptMaster* GetDeclarativeUserScriptMasterByExtension(
-      const ExtensionId& extension_id) override;
 
  private:
   content::BrowserContext* browser_context_;  // Not owned.