Fix cases that initialized StringTokenizer with a temporary.

base/string_tokenizer.h

 // Copyright (c) 2006-2008 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 BASE_STRING_TOKENIZER_H_
 #define BASE_STRING_TOKENIZER_H_
 
 #include <string>
 
 // StringTokenizerT is a simple string tokenizer class.  It works like an
 // iterator that with each step (see the Advance method) updates members that
 // refer to the next token in the input string.  The user may optionally
 // configure the tokenizer to return delimiters.
 //
+// Warning: be careful not to pass a C string into the 2-arg constructor:
+// StringTokenizer t("this is a test", " ");  // WRONG
+// This will create a temporary std::string, save the begin() and end()
+// iterators, and then the string will be freed before we actually start
+// tokenizing it.
+// Instead, use a std::string or use the 3 arg constructor of CStringTokenizer.
+//
 //
 // EXAMPLE 1:
 //
-//   StringTokenizer t("this is a test", " ");
+//   char input[] = "this is a test";
+//   CStringTokenizer t(input, input + strlen(input), " ");
 //   while (t.GetNext()) {
 //     printf("%s\n", t.token().c_str());
 //   }
 //
 // Output:
 //
 //   this
 //   is
 //   a
 //   test
 //
 //
 // EXAMPLE 2:
 //
-//   StringTokenizer t("no-cache=\"foo, bar\", private", ", ");
+//   std::string input = "no-cache=\"foo, bar\", private";
+//   StringTokenizer t(input, ", ");
 //   t.set_quote_chars("\"");
 //   while (t.GetNext()) {
 //     printf("%s\n", t.token().c_str());
 //   }
 //
 // Output:
 //
 //   no-cache="foo, bar"
 //   private
 //
@@ skipping 34 matching lines @@
 class StringTokenizerT {
  public:
   typedef typename str::value_type char_type;
 
   // Options that may be pass to set_options()
   enum {
     // Specifies the delimiters should be returned as tokens
     RETURN_DELIMS = 1 << 0,
   };
 
+  // The string object must live longer than the tokenizer.  (In particular this
+  // should not be constructed with a temporary.)
   StringTokenizerT(const str& string,
                    const str& delims) {
     Init(string.begin(), string.end(), delims);
   }
 
   StringTokenizerT(const_iterator string_begin,
                    const_iterator string_end,
                    const str& delims) {
     Init(string_begin, string_end, delims);
   }
@@ skipping 95 matching lines @@
   bool token_is_delim_;
 };
 
 typedef StringTokenizerT<std::string, std::string::const_iterator>
     StringTokenizer;
 typedef StringTokenizerT<std::wstring, std::wstring::const_iterator>
     WStringTokenizer;
 typedef StringTokenizerT<std::string, const char*> CStringTokenizer;
 
 #endif  // BASE_STRING_TOKENIZER_H_