Introduce WebRequestEventRouterDelegate.

extensions/browser/api/extensions_api_client.h

Index: extensions/browser/api/extensions_api_client.h
diff --git a/extensions/browser/api/extensions_api_client.h b/extensions/browser/api/extensions_api_client.h
index 77fb90970e342ac0ab18533216673978f8ebf600..cd367c1703576c6c709b696a5cc4b8d63939168f 100644
--- a/extensions/browser/api/extensions_api_client.h
+++ b/extensions/browser/api/extensions_api_client.h
@@ -31,6 +31,7 @@ class WebViewGuest;
 class WebViewGuestDelegate;
 class WebViewPermissionHelper;
 class WebViewPermissionHelperDelegate;
+class WebRequestEventRouterDelegate;
 class SettingsObserver;
 class SettingsStorageFactory;
 class ValueStoreCache;
@@ -89,6 +90,10 @@ class ExtensionsAPIClient {
       const RulesRegistry::WebViewKey& webview_key,
       const std::string& event_name);
 
+  // Creates a delegate for WebRequestEventRouter.
+  virtual WebRequestEventRouterDelegate* CreateWebRequestEventRouterDelegate()
+      const;
+
   // NOTE: If this interface gains too many methods (perhaps more than 20) it
   // should be split into one interface per API.
 };