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

ios/chrome/browser/ui/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/ui_util.h"
 
 #include <stddef.h>
 #import <UIKit/UIKit.h>
 
 #include "base/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 TEST(UIUtilTest, AlignToPixel) {
   CGFloat scale = [[UIScreen mainScreen] scale];
   // Pick a few interesting values: already aligned, aligned on retina, and
   // some unaligned values that would round differently. Ensure that all are
   // "integer" values within <1 of the original value in the scaled space.
   CGFloat test_values[] = {10.0, 55.5, 3.14159, 2.71828};
   const CGFloat kMaxAlignDelta = 0.9999;
   size_t value_count = arraysize(test_values);
   for (unsigned int i = 0; i < value_count; ++i) {
     CGFloat aligned = AlignValueToPixel(test_values[i]);
@@ skipping 270 matching lines @@
   originalSize = CGSizeMake(50, 100);
   targetSize = CGSizeMake(40, 60);
   expectedProjection = CGRectMake(0, 0, 40, 80);
   expectedRevisedSize = expectedProjection.size;
   CalculateProjection(originalSize, targetSize,
                       ProjectionMode::kAspectFillNoClipping, revisedSize,
                       projection);
   EXPECT_EQ_RECT(expectedProjection, projection);
   EXPECT_EQ_SIZE(expectedRevisedSize, revisedSize);
 }