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

ui/ios/uikit_util.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.
+
+#include "ui/ios/uikit_util.h"
+
+#import <UIKit/UIKit.h>
+
+namespace ui {
+
+CGFloat alignValueToUpperPixel(CGFloat value) {
+  CGFloat scale = [[UIScreen mainScreen] scale];
+  return ceil(value * scale) / scale;

[stuartmorgan, 2014/09/04 22:16:11]

std::ceil so it does the right thing with 64-bit?

[lliabraa, 2014/09/05 16:53:44]

Done.

+}
+
+CGSize alignSizeToUpperPixel(CGSize size) {
+  return CGSizeMake(alignValueToUpperPixel(size.width),
+      alignValueToUpperPixel(size.height));

[stuartmorgan, 2014/09/04 22:16:11]

Should align inside the (

[lliabraa, 2014/09/05 16:53:45]

Done.

+}
+
+} // namespace ui