Remove unavailable API in FlutterDartProject.h (#4723)

shell/platform/darwin/ios/framework/Headers/Flutter.h

@@ -8,6 +8,9 @@
 /**
  BREAKING CHANGES:
 
+ February 28, 2018: Removed "initWithFLXArchive" and
+ "initWithFLXArchiveWithScriptSnapshot".
+
  January 15, 2018: Marked "initWithFLXArchive" and
  "initWithFLXArchiveWithScriptSnapshot" as unavailable following the
  deprecation from December 11, 2017. Scheduled to be removed on February

shell/platform/darwin/ios/framework/Headers/FlutterDartProject.h

@@ -14,18 +14,6 @@ FLUTTER_EXPORT
 
 - (instancetype)initWithPrecompiledDartBundle:(NSBundle*)bundle NS_DESIGNATED_INITIALIZER;
 
-- (instancetype)initWithFLXArchive:(NSURL*)archiveURL
-                          dartMain:(NSURL*)dartMainURL
-                          packages:(NSURL*)dartPackages NS_DESIGNATED_INITIALIZER
-    FLUTTER_UNAVAILABLE(
-        "This initializer is no longer available. See the deprecation message from "
-        "December 11, 2017 in Flutter.h. Instead, use [initWithFlutterAssets].");
-
-- (instancetype)initWithFLXArchiveWithScriptSnapshot:(NSURL*)archiveURL NS_DESIGNATED_INITIALIZER
-    FLUTTER_UNAVAILABLE(
-        "This initializer is no longer available. See the deprecation message from "
-        "December 11, 2017 in Flutter.h. Instead, use [initWithFlutterAssetsWithScriptSnapshot].");
-
 - (instancetype)initWithFlutterAssets:(NSURL*)flutterAssetsURL
                              dartMain:(NSURL*)dartMainURL
                              packages:(NSURL*)dartPackages NS_DESIGNATED_INITIALIZER;