diff -r 000000000000 -r 6474c204b198 toolkit/crashreporter/google-breakpad/src/common/unique_string.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/crashreporter/google-breakpad/src/common/unique_string.cc	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,110 @@
+// Copyright (c) 2013 Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <string>
+#include <map>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "common/unique_string.h"
+
+namespace google_breakpad {
+
+///////////////////////////////////////////////////////////////////
+// UniqueString
+//
+class UniqueString {
+ public:
+  UniqueString(string str) { str_ = strdup(str.c_str()); }
+  ~UniqueString() { free(reinterpret_cast<void*>(const_cast<char*>(str_))); }
+  const char* str_;
+};
+
+class UniqueStringUniverse {
+ public:
+  UniqueStringUniverse() {};
+  const UniqueString* FindOrCopy(string str) {
+    std::map<string, UniqueString*>::iterator it = map_.find(str);
+    if (it == map_.end()) {
+      UniqueString* ustr = new UniqueString(str);
+      map_[str] = ustr;
+      return ustr;
+    } else {
+      return it->second;
+    }
+  }
+ private:
+  std::map<string, UniqueString*> map_;
+};
+
+//
+///////////////////////////////////////////////////////////////////
+
+
+static UniqueStringUniverse* sUSU = NULL;
+
+
+// This isn't threadsafe.
+const UniqueString* ToUniqueString(string str) {
+  if (!sUSU) {
+    sUSU = new UniqueStringUniverse();
+  }
+  return sUSU->FindOrCopy(str);
+}
+
+// This isn't threadsafe.
+const UniqueString* ToUniqueString_n(const char* str, size_t n) {
+  if (!sUSU) {
+    sUSU = new UniqueStringUniverse();
+  }
+  string key(str, n);
+  return sUSU->FindOrCopy(key);
+}
+
+const char Index(const UniqueString* us, int ix)
+{
+  return us->str_[ix];
+}
+
+const char* const FromUniqueString(const UniqueString* ustr)
+{
+  return ustr->str_;
+}
+
+int StrcmpUniqueString(const UniqueString* us1, const UniqueString* us2) {
+  return strcmp(us1->str_, us2->str_);
+}
+
+bool LessThan_UniqueString(const UniqueString* us1, const UniqueString* us2) {
+  int r = StrcmpUniqueString(us1, us2);
+  return r < 0;
+}
+
+}  // namespace google_breakpad