Remove DevToolsSecurity check from initial flutter doctor (#16007)

packages/flutter_tools/lib/src/ios/ios_workflow.dart

@@ -94,13 +94,6 @@ class IOSWorkflow extends DoctorValidator implements Workflow {
           'Launch Xcode and install additional required components when prompted.'
         ));
       }
-      if ((await macDevMode).contains('disabled')) {
-        xcodeStatus = ValidationType.partial;
-        messages.add(new ValidationMessage.error(
-          'Your Mac needs to enabled for developer mode before using Xcode for the first time.\n'
-          'Run \'sudo DevToolsSecurity -enable\' to enable developer mode.'
-        ));
-      }
 
     } else {
       xcodeStatus = ValidationType.missing;

packages/flutter_tools/test/ios/ios_workflow_test.dart

@@ -111,22 +111,6 @@ void main() {
       CocoaPods: () => cocoaPods,
     });
 
-    testUsingContext('Emits partial status when Mac dev mode was never enabled', () async {
-      when(xcode.isInstalled).thenReturn(true);
-      when(xcode.versionText)
-          .thenReturn('Xcode 8.2.1\nBuild version 8C1002\n');
-      when(xcode.isInstalledAndMeetsVersionCheck).thenReturn(true);
-      when(xcode.eulaSigned).thenReturn(true);
-      when(xcode.isSimctlInstalled).thenReturn(true);
-      final IOSWorkflowTestTarget workflow = new IOSWorkflowTestTarget(macDevMode: 'Developer mode is currently disabled.');
-      final ValidationResult result = await workflow.validate();
-      expect(result.type, ValidationType.partial);
-    }, overrides: <Type, Generator>{
-      IMobileDevice: () => iMobileDevice,
-      Xcode: () => xcode,
-      CocoaPods: () => cocoaPods,
-    });
-
     testUsingContext('Emits partial status when python six not installed', () async {
       when(xcode.isInstalled).thenReturn(true);
       when(xcode.versionText)
@@ -354,11 +338,9 @@ class IOSWorkflowTestTarget extends IOSWorkflow {
     bool hasIosDeploy: true,
     String iosDeployVersionText: '1.9.2',
     bool hasIDeviceInstaller: true,
-    String macDevMode: 'Developer mode is already enabled.',
   }) : hasIosDeploy = new Future<bool>.value(hasIosDeploy),
        iosDeployVersionText = new Future<String>.value(iosDeployVersionText),
-       hasIDeviceInstaller = new Future<bool>.value(hasIDeviceInstaller),
-       macDevMode = new Future<String>.value(macDevMode);
+       hasIDeviceInstaller = new Future<bool>.value(hasIDeviceInstaller);
 
   @override
   final bool hasPythonSixModule;
@@ -374,7 +356,4 @@ class IOSWorkflowTestTarget extends IOSWorkflow {
 
   @override
   final Future<bool> hasIDeviceInstaller;
-
-  @override
-  final Future<String> macDevMode;
 }