Revert of Convert //net and //chromecast to std::unordered_*

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 <stddef.h>
 
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 
 namespace net {
 
+#if defined(COMPILER_MSVC)
+struct StringPieceCaseCompare {
+  static const size_t bucket_size = 4;
+
+  size_t operator()(const base::StringPiece& sp) const {
+    // based on __stl_string_hash in http://www.sgi.com/tech/stl/string
+    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;
+  }
+
+  bool operator()(const base::StringPiece& sp1,
+                  const base::StringPiece& sp2) const {
+    size_t len1 = sp1.length();
+    size_t len2 = sp2.length();
+    bool sp1_shorter = len1 < len2;
+    size_t len = sp1_shorter ? len1 : len2;
+
+    int rv = 0;
+    for (size_t i = 0; i < len; i++) {
+      char sp1_lower = base::ToLowerASCII(sp1[i]);
+      char sp2_lower = base::ToLowerASCII(sp2[i]);
+      if (sp1_lower < sp2_lower) {
+        rv = -1;
+        break;
+      }
+      if (sp1_lower > sp2_lower) {
+        rv = 1;
+        break;
+      }
+    }
+
+    if (rv == 0) {
+      return sp1_shorter;
+    }
+    return rv < 0;
+  }
+};
+#else  // COMPILER_MSVC
 struct StringPieceCaseHash {
   size_t operator()(const base::StringPiece& sp) const {
     // based on __stl_string_hash in http://www.sgi.com/tech/stl/string
     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 StringPieceCaseEqual {
   bool operator()(const base::StringPiece& piece1,
                   const base::StringPiece& piece2) const {
     return base::EqualsCaseInsensitiveASCII(piece1, piece2);
   }
 };
 
 }  // namespace net
 
 #endif  // NET_TOOLS_BALSA_STRING_PIECE_UTILS_H_