remove unnecessary private dependency

Author: Chris Yang

shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm

@@ -5,7 +5,6 @@
 #import <OCMock/OCMock.h>
 #import <XCTest/XCTest.h>
 
-#include "flutter/flow/surface_frame.h"
 #import "flutter/shell/platform/darwin/common/framework/Headers/FlutterBinaryMessenger.h"
 #import "flutter/shell/platform/darwin/common/framework/Headers/FlutterMacros.h"
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterPlatformViews.h"