Replace base::str[n]casecmp with helper functions.

net/tools/balsa/string_piece_utils.h

 // Copyright 2013 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 NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_
 #define NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_
 
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 
@@ skipping 47 matching lines @@
     size_t hash_val = 0;
     for (base::StringPiece::const_iterator it = sp.begin();
          it != sp.end(); ++it) {
       hash_val = 5 * hash_val + base::ToLowerASCII(*it);
     }
     return hash_val;
   }
 };
 #endif  // COMPILER_MSVC
 
-struct StringPieceUtils {
-  // ASCII case-insensitive equality.
-  static bool EqualIgnoreCase(const base::StringPiece& piece1,
-                              const base::StringPiece& piece2) {
-    base::StringPiece::const_iterator p1i = piece1.begin();
-    base::StringPiece::const_iterator p2i = piece2.begin();
-    if (piece1.empty() && piece2.empty()) {
-      return true;
-    } else if (piece1.size() != piece2.size()) {
-      return false;
-    }
-    while (p1i != piece1.end() && p2i != piece2.end()) {
-      if (base::ToLowerASCII(*p1i) != base::ToLowerASCII(*p2i))
-        return false;
-      ++p1i;
-      ++p2i;
-    }
-    return true;
-  }
-};
-
 struct StringPieceCaseEqual {
   bool operator()(const base::StringPiece& piece1,
                   const base::StringPiece& piece2) const {
-    return StringPieceUtils::EqualIgnoreCase(piece1, piece2);
+    return base::EqualsCaseInsensitiveASCII(piece1, piece2);
   }
 };
 
 }  // namespace net
 
 #endif  // NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_