Implement declarativeContent API.

chrome/browser/extensions/tab_helper.h

Index: chrome/browser/extensions/tab_helper.h
diff --git a/chrome/browser/extensions/tab_helper.h b/chrome/browser/extensions/tab_helper.h
index 0228adc8a4f6cf4fd5f8742d8a4c4e7e7dbefa45..e7511e9004afc260002b4f767495be4d766c2696 100644
--- a/chrome/browser/extensions/tab_helper.h
+++ b/chrome/browser/extensions/tab_helper.h
@@ -28,6 +28,7 @@ struct LoadCommittedDetails;
 }
 
 namespace extensions {
+class ContentRulesRegistry;
 class Extension;
 class LocationBarController;
 class ScriptBadgeController;
@@ -193,6 +194,7 @@ class TabHelper : public content::WebContentsObserver,
       const ScriptExecutionObserver::ExecutingScriptsMap& extension_ids,
       int32 page_id,
       const GURL& on_url);
+  void OnWatchedPageChange(const std::vector<std::string>& css_selectors);
 
   // App extensions related methods:
 
@@ -267,6 +269,8 @@ class TabHelper : public content::WebContentsObserver,
 
   scoped_ptr<ScriptBubbleController> script_bubble_controller_;
 
+  ContentRulesRegistry* content_rules_registry_;
+
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(TabHelper);