Add a couple UIKit util functions in src/ui/ios/

ui/ios/uikit_util_unittest.mm

+// Copyright 2014 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 <Foundation/Foundation.h>
+
+#include "base/basictypes.h"
+#include "testing/platform_test.h"
+#import "ui/ios/uikit_util.h"
+
+namespace {
+
+typedef PlatformTest UIKitUtilTest;
+
+TEST_F(UIKitUtilTest, AlignValueToUpperPixel) {
+   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, 3.1, 2.9 };
+   const CGFloat kMaxAlignDelta = 0.9999;
+   size_t value_count = arraysize(test_values);
+   for (unsigned int i = 0; i < value_count; ++i) {
+     CGFloat aligned = ui::AlignValueToUpperPixel(test_values[i]);
+     EXPECT_FLOAT_EQ(aligned * scale, floor(aligned * scale));
+     EXPECT_NEAR(aligned * scale, test_values[i] * scale, kMaxAlignDelta);
+   }
+}
+
+TEST_F(UIKitUtilTest, AlignSizeToUpperPixel) {
+  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, 3.1, 2.9 };
+  const CGFloat kMaxAlignDelta = 0.9999;
+  size_t value_count = arraysize(test_values);
+  for (unsigned int i = 0; i < value_count; ++i) {
+    CGFloat width = test_values[i];
+    CGFloat height = test_values[(i + 1) % value_count];
+    CGSize alignedSize = ui::AlignSizeToUpperPixel(CGSizeMake(width, height));
+    EXPECT_FLOAT_EQ(floor(alignedSize.width * scale),
+                    alignedSize.width * scale);
+    EXPECT_FLOAT_EQ(floor(alignedSize.height * scale),
+                    alignedSize.height * scale);
+    EXPECT_NEAR(width * scale, alignedSize.width * scale, kMaxAlignDelta);
+    EXPECT_NEAR(height * scale, alignedSize.height * scale, kMaxAlignDelta);
+  }
+}
+
+}  // namespace