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 08c6e3196ddf3da9e940f3e2185c5d56fb91c110..879607d114167a5df2590d3d6fa706f5357b3a1c 100644
--- a/extensions/browser/api/extensions_api_client.h
+++ b/extensions/browser/api/extensions_api_client.h
@@ -32,6 +32,7 @@ class WebViewGuest;
 class WebViewGuestDelegate;
 class WebViewPermissionHelper;
 class WebViewPermissionHelperDelegate;
+class WebRequestEventRouterDelegate;
 class SettingsObserver;
 class SettingsStorageFactory;
 class ValueStoreCache;
@@ -90,6 +91,10 @@ 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.
 };