Fix a 'type-limits' warning in StringSlicer::FindValidBoundaryAfter

ui/gfx/text_elider.cc

 // Copyright (c) 2012 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.
 //
 // This file implements utility functions for eliding and formatting UI text.
 //
 // Note that several of the functions declared in text_elider.h are implemented
 // in this file using helper classes in an unnamed namespace.
 
 #include "ui/gfx/text_elider.h"
@@ skipping 129 matching lines @@
 size_t StringSlicer::FindValidBoundaryBefore(size_t index) const {
   DCHECK_LE(index, text_.length());
   if (index != text_.length())
     U16_SET_CP_START(text_.data(), 0, index);
   return index;
 }
 
 size_t StringSlicer::FindValidBoundaryAfter(size_t index) const {
   DCHECK_LE(index, text_.length());
   if (index != text_.length())
-    U16_SET_CP_LIMIT(text_.data(), 0, index, text_.length());
+    U16_SET_CP_LIMIT(text_.data(), 0, index, -1);

[Peter Kasting, 2014/10/29 17:33:38]

For safety, this should use c_str() instead of data(), as the former is
guaranteed to be null-terminated and the latter is not.  Passing a negative
length is supposedly only legal with a null-terminated string.

(The macro here doesn't end up caring about such a thing, but it might in the
future.)

[Ben Chan, 2014/10/29 17:36:01]

Done.

   return index;
 }
 
 base::string16 ElideFilename(const base::FilePath& filename,
                              const FontList& font_list,
                              float available_pixel_width) {
 #if defined(OS_WIN)
   base::string16 filename_utf16 = filename.value();
   base::string16 extension = filename.Extension();
   base::string16 rootname = filename.BaseName().RemoveExtension().value();
@@ skipping 656 matching lines @@
     index = char_iterator.getIndex();
   } else {
     // String has leading whitespace, return the elide string.
     return kElideString;
   }
 
   return string.substr(0, index) + kElideString;
 }
 
 }  // namespace gfx