fix http client

ios/Flutter/Flutter.framework/Headers/FlutterPlugin.h

@@ -21,7 +21,7 @@ NS_ASSUME_NONNULL_BEGIN
  Defines a set of optional callback methods and a method to set up the plugin
  and register it to be called by other application components.
  */
-@protocol FlutterPlugin<NSObject>
+@protocol FlutterPlugin <NSObject>
 @required
 /**
  Registers this plugin.
@@ -130,12 +130,28 @@ NS_ASSUME_NONNULL_BEGIN
                completionHandler:(void (^)(BOOL succeeded))completionHandler
     API_AVAILABLE(ios(9.0));
 
+/**
+ Called if this plugin has been registered for `UIApplicationDelegate` callbacks.
+
+ - Returns: `YES` if this plugin handles the request.
+ */
+- (BOOL)application:(UIApplication*)application
+    handleEventsForBackgroundURLSession:(nonnull NSString*)identifier
+                      completionHandler:(nonnull void (^)())completionHandler;
+
+/**
+ Called if this plugin has been registered for `UIApplicationDelegate` callbacks.
+
+ - Returns: `YES` if this plugin handles the request.
+ */
+- (BOOL)application:(UIApplication*)application
+    performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler;
 @end
 
 /**
  Registration context for a single `FlutterPlugin`.
  */
-@protocol FlutterPluginRegistrar<NSObject>
+@protocol FlutterPluginRegistrar <NSObject>
 /**
  Returns a `FlutterBinaryMessenger` for creating Dart/iOS communication
  channels to be used by the plugin.
@@ -211,7 +227,7 @@ NS_ASSUME_NONNULL_BEGIN
  Plugins are identified by unique string keys, typically the name of the
  plugin's main class.
  */
-@protocol FlutterPluginRegistry<NSObject>
+@protocol FlutterPluginRegistry <NSObject>
 /**
  Returns a registrar for registering a plugin.