[ObjC ARC] Converts ios/chrome/browser/ui/main:unit_tests to ARC.

ios/chrome/browser/ui/main/main_view_controller_unittest.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/ui/main/main_view_controller.h"
 
 #import <UIKit/UIKit.h>
 
-#include "base/mac/scoped_nsobject.h"
 #include "testing/gtest_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface HiddenStatusBarViewController : UIViewController
 @end
 
 @implementation HiddenStatusBarViewController
 - (BOOL)prefersStatusBarHidden {
   return YES;
 }
 @end
 
 @interface MockViewController : UIViewController
 @property(nonatomic, readonly) NSInteger didMoveToParentViewControllerCount;
-@property(nonatomic, readonly) id didMoveToParentViewControllerArgument;
+@property(weak, nonatomic, readonly) id didMoveToParentViewControllerArgument;

[marq (ping after 24h), 2017/02/10 11:02:40]

Nit: Prefer to keep atomicity first, then storage policy, then
readonly/readwrite. So:

@property(nonatomic, weak, readonly)

(here and below).

 @property(nonatomic, readonly) NSInteger willMoveToParentViewControllerCount;
-@property(nonatomic, readonly) id willMoveToParentViewControllerArgument;
+@property(weak, nonatomic, readonly) id willMoveToParentViewControllerArgument;
 @end
 
 @implementation MockViewController
 @synthesize didMoveToParentViewControllerCount =
     _didMoveToParentViewControllerCount;
 @synthesize didMoveToParentViewControllerArgument =
     _didMoveToParentViewControllerArgument;
 @synthesize willMoveToParentViewControllerCount =
     _willMoveToParentViewControllerCount;
 @synthesize willMoveToParentViewControllerArgument =
     _willMoveToParentViewControllerArgument;
 
 - (void)didMoveToParentViewController:(UIViewController*)parent {
   _didMoveToParentViewControllerCount++;
   _didMoveToParentViewControllerArgument = parent;
 }
 
 - (void)willMoveToParentViewController:(UIViewController*)parent {
   _willMoveToParentViewControllerCount++;
   _willMoveToParentViewControllerArgument = parent;
 }
 
 @end
 
 namespace {
 
 TEST(MainViewControllerTest, ActiveVC) {
-  base::scoped_nsobject<MainViewController> main_view_controller(
-      [[MainViewController alloc] init]);
-  base::scoped_nsobject<UIViewController> child_view_controller_1(
-      [[UIViewController alloc] init]);
-  base::scoped_nsobject<UIViewController> child_view_controller_2(
-      [[UIViewController alloc] init]);
+  MainViewController* main_view_controller = [[MainViewController alloc] init];
+  UIViewController* child_view_controller_1 = [[UIViewController alloc] init];
+  UIViewController* child_view_controller_2 = [[UIViewController alloc] init];
 
   // Test that the active view controller is always the first child view
   // controller.
   EXPECT_EQ(nil, [main_view_controller activeViewController]);
   [main_view_controller addChildViewController:child_view_controller_1];
-  EXPECT_EQ(child_view_controller_1.get(),
+  EXPECT_EQ(child_view_controller_1,
             [main_view_controller activeViewController]);
   [main_view_controller addChildViewController:child_view_controller_2];
-  EXPECT_EQ(child_view_controller_1.get(),
+  EXPECT_EQ(child_view_controller_1,
             [main_view_controller activeViewController]);
   [child_view_controller_1 removeFromParentViewController];
-  EXPECT_EQ(child_view_controller_2.get(),
+  EXPECT_EQ(child_view_controller_2,
             [main_view_controller activeViewController]);
 }
 
 TEST(MainViewControllerTest, SetActiveVC) {
-  base::scoped_nsobject<MainViewController> main_view_controller(
-      [[MainViewController alloc] init]);
+  MainViewController* main_view_controller = [[MainViewController alloc] init];
   CGRect windowRect = CGRectMake(0, 0, 200, 200);
   [main_view_controller view].frame = windowRect;
 
-  base::scoped_nsobject<MockViewController> child_view_controller_1(
-      [[MockViewController alloc] init]);
+  MockViewController* child_view_controller_1 =
+      [[MockViewController alloc] init];
   [child_view_controller_1 view].frame = CGRectMake(0, 0, 10, 10);
 
   [main_view_controller setActiveViewController:child_view_controller_1];
-  EXPECT_EQ(child_view_controller_1.get(),
+  EXPECT_EQ(child_view_controller_1,
             [[main_view_controller childViewControllers] firstObject]);
   EXPECT_EQ([child_view_controller_1 view],
             [[main_view_controller view].subviews firstObject]);
   EXPECT_NSEQ(NSStringFromCGRect(windowRect),
               NSStringFromCGRect([child_view_controller_1 view].frame));
   EXPECT_EQ(1, [child_view_controller_1 didMoveToParentViewControllerCount]);
-  EXPECT_EQ(main_view_controller.get(),
+  EXPECT_EQ(main_view_controller,
             [child_view_controller_1 didMoveToParentViewControllerArgument]);
   // Expect there to have also been an automatic call to
   // -willMoveToParentViewController.
   EXPECT_EQ(1, [child_view_controller_1 willMoveToParentViewControllerCount]);
-  EXPECT_EQ(main_view_controller.get(),
+  EXPECT_EQ(main_view_controller,
             [child_view_controller_1 willMoveToParentViewControllerArgument]);
 
-  base::scoped_nsobject<UIViewController> child_view_controller_2(
-      [[UIViewController alloc] init]);
+  UIViewController* child_view_controller_2 = [[UIViewController alloc] init];
   [main_view_controller setActiveViewController:child_view_controller_2];
-  EXPECT_EQ(child_view_controller_2.get(),
+  EXPECT_EQ(child_view_controller_2,
             [[main_view_controller childViewControllers] firstObject]);
   EXPECT_EQ(1U, [[main_view_controller childViewControllers] count]);
   EXPECT_EQ(nil, [[child_view_controller_1 view] superview]);
   EXPECT_EQ(2, [child_view_controller_1 willMoveToParentViewControllerCount]);
   EXPECT_EQ(nil,
             [child_view_controller_1 willMoveToParentViewControllerArgument]);
   // Expect there to have also been an automatic call to
   // -didMoveToParentViewController.
   EXPECT_EQ(2, [child_view_controller_1 willMoveToParentViewControllerCount]);
   EXPECT_EQ(nil,
             [child_view_controller_1 didMoveToParentViewControllerArgument]);
 }
 
 TEST(MainViewControllerTest, StatusBar) {
-  base::scoped_nsobject<MainViewController> main_view_controller(
-      [[MainViewController alloc] init]);
+  MainViewController* main_view_controller = [[MainViewController alloc] init];
   // MVC needs to be the root view controller for this to work, so save the
   // current one and restore it at the end of the test.
   UIViewController* root_view_controller =
       [[[UIApplication sharedApplication] keyWindow] rootViewController];
   [[UIApplication sharedApplication] keyWindow].rootViewController =
       main_view_controller;
-  base::scoped_nsobject<UIViewController> status_bar_visible_view_controller(
-      [[UIViewController alloc] init]);
+  UIViewController* status_bar_visible_view_controller =
+      [[UIViewController alloc] init];
   [main_view_controller
       setActiveViewController:status_bar_visible_view_controller];
   // Check if the status bar is hidden by testing if the status bar rect is
   // CGRectZero.
   EXPECT_FALSE(CGRectEqualToRect(
       [UIApplication sharedApplication].statusBarFrame, CGRectZero));
-  base::scoped_nsobject<HiddenStatusBarViewController>
-      status_bar_hidden_view_controller(
-          [[HiddenStatusBarViewController alloc] init]);
+  HiddenStatusBarViewController* status_bar_hidden_view_controller =
+      [[HiddenStatusBarViewController alloc] init];
   [main_view_controller
       setActiveViewController:status_bar_hidden_view_controller];
   EXPECT_EQ([main_view_controller childViewControllerForStatusBarHidden],
-            status_bar_hidden_view_controller.get());
+            status_bar_hidden_view_controller);
   EXPECT_TRUE(CGRectEqualToRect(
       [UIApplication sharedApplication].statusBarFrame, CGRectZero));
   [[UIApplication sharedApplication] keyWindow].rootViewController =
       root_view_controller;
 }
 
 }  // namespace