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

ui/ios/uikit_util.h

+// 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.
+
+#ifndef UI_IOS_UIKIT_UTIL_H_
+#define UI_IOS_UIKIT_UTIL_H_
+
+#import <UIKit/UIKit.h>
+
+#include "base/compiler_specific.h"
+
+// UI Util containing functions that require UIKit.
+
+namespace ui {
+
+// Returns the closest pixel-aligned value higher than |value|, taking the scale
+// factor into account. At a scale of 1, equivalent to ceil().
+CGFloat AlignValueToUpperPixel(CGFloat value) WARN_UNUSED_RESULT;
+
+// Returns the size resulting from applying AlignToUpperPixel to both
+// components.
+CGSize AlignSizeToUpperPixel(CGSize size) WARN_UNUSED_RESULT;
+
+} // namespace ui
+
+#endif  // UI_IOS_UIKIT_UTIL_H_