Upstream NSString+CrStringDrawing changes.

ui/gfx/ios/NSString+CrStringDrawing.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 "ui/gfx/ios/NSString+CrStringDrawing.h"
 
 #include "base/logging.h"
 #include "ui/gfx/ios/uikit_util.h"
 
 @implementation NSString (CrStringDrawing)
@@ skipping 19 matching lines @@
 }
 
 - (CGSize)cr_sizeWithFont:(UIFont*)font {
   if (!font)
     return CGSizeZero;
   NSDictionary* attributes = @{ NSFontAttributeName : font };
   CGSize size = [self sizeWithAttributes:attributes];
   return CGSizeMake(ceil(size.width), ceil(size.height));
 }
 
+- (NSString*)cr_stringByCuttingToIndex:(NSUInteger)index {
+  if (index == 0)
+    return @"";
+  if (index >= [self length])
+    return [[self retain] autorelease];
+  return [[self substringToIndex:index - 1] stringByAppendingString:@"…"];

[rohitrao (ping after 24h), 2015/03/10 18:35:53]

Parens around (index - 1), perhaps?

[Eugene But (OOO till 7-30), 2015/03/10 18:45:05]

Will do in followup CL per offline discussion.

+}
+
+- (NSString*)cr_stringByElidingToFitSize:(CGSize)bounds {
+  CGSize sizeForGuess = CGSizeMake(bounds.width, CGFLOAT_MAX);
+  // Use binary search on the string's length.
+  size_t lo = 0;
+  size_t hi = [self length];
+  size_t guess = 0;
+  for (guess = (lo + hi) / 2; lo < hi; guess = (lo + hi) / 2) {
+    NSString* tempString = [self cr_stringByCuttingToIndex:guess];
+    UIFont* font = [UIFont systemFontOfSize:[UIFont labelFontSize]];
+    CGSize sizeGuess =
+        [tempString cr_boundingSizeWithSize:sizeForGuess font:font];
+    if (sizeGuess.height > bounds.height) {

[rohitrao (ping after 24h), 2015/03/10 18:35:53]

Why do we compare heights here?

[rohitrao (ping after 24h), 2015/03/10 18:37:20]

Oh, I think this is testing how many lines are in the output.  Ok.

+      hi = guess - 1;
+      if (hi < lo)
+        hi = lo;
+    } else {
+      lo = guess + 1;
+    }
+  }
+  return [self cr_stringByCuttingToIndex:lo];
+}
+
 @end