Add NSString category for providing iOS6-style string drawing APIs.

ui/ios/NSString+CrStringDrawing.h

Index: ui/ios/NSString+CrStringDrawing.h
diff --git a/ui/ios/NSString+CrStringDrawing.h b/ui/ios/NSString+CrStringDrawing.h
new file mode 100644
index 0000000000000000000000000000000000000000..41511315f668526f918b32ff0942da564b2bd387
--- /dev/null
+++ b/ui/ios/NSString+CrStringDrawing.h
@@ -0,0 +1,20 @@
+// 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_NSSTRING_CR_STRING_DRAWING_H_
+#define UI_IOS_NSSTRING_CR_STRING_DRAWING_H_
+
+#import <UIKit/UIKit.h>
+
+@interface NSString (CrStringDrawing)
+
+// Returns the size of the string if it were to be rendered with the specified
+// font on a single line.
+// The following method provides an API like -sizeWithFont: which was deprecated
+// in iOS 7 in favor of -sizeWithAttributes:.
+- (CGSize)cr_sizeWithFont:(UIFont*)font;
+
+@end
+
+#endif  // UI_IOS_NSSTRING_CR_STRING_DRAWING_H_