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

ios/chrome/browser/ui/uikit_ui_util_unittest.mm

 // Copyright 2012 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.
 
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/browser/ui/ui_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #import "third_party/ocmock/OCMock/OCMock.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 void ExpectInterpolatedColor(UIColor* firstColor,
                              UIColor* secondColor,
                              CGFloat percentage,
                              CGFloat expectedValue) {
   UIColor* interpolatedColor =
       InterpolateFromColorToColor(firstColor, secondColor, percentage);
   CGFloat r, g, b, a;
   [interpolatedColor getRed:&r green:&g blue:&b alpha:&a];
   EXPECT_FLOAT_EQ(expectedValue, r);
   EXPECT_FLOAT_EQ(expectedValue, g);
   EXPECT_FLOAT_EQ(expectedValue, b);
   EXPECT_FLOAT_EQ(1.0, a);
 }
 
 // Verify the assumption about UIViewController that on iPad all orientations
 // are supported, and all orientations but Portrait Upside-Down on iPhone and
 // iPod Touch.
 TEST(UIKitUIUtilTest, UIViewControllerSupportedOrientationsTest) {
-  base::scoped_nsobject<UIViewController> viewController(
-      [[UIViewController alloc] initWithNibName:nil bundle:nil]);
+  UIViewController* viewController =
+      [[UIViewController alloc] initWithNibName:nil bundle:nil];
   if (IsIPadIdiom()) {
     EXPECT_EQ(UIInterfaceOrientationMaskAll,
               [viewController supportedInterfaceOrientations]);
   } else {
     EXPECT_EQ(UIInterfaceOrientationMaskAllButUpsideDown,
               [viewController supportedInterfaceOrientations]);
   }
 }
 
 TEST(UIKitUIUtilTest, TestGetUiFont) {
@@ skipping 111 matching lines @@
   ASSERT_EQ(kCGColorSpaceModelMonochrome,
             CGColorSpaceGetModel(CGColorGetColorSpace(black.CGColor)));
 
   // Interpolate between monochrome and rgb.
   ExpectInterpolatedColor(black, rgb, 0.5, 0.1);
   // Interpolate between two monochrome colors.
   ExpectInterpolatedColor(black, white, 0.3, 0.3);
 }
 
 }  // namespace