Added a new SafeSPrintf() function that implements snprintf() in an async-safe-fashion

base/debug/stack_trace.h

 // 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.
 
 #ifndef BASE_DEBUG_STACK_TRACE_H_
 #define BASE_DEBUG_STACK_TRACE_H_
 
 #include <iosfwd>
 #include <string>
 
@@ skipping 59 matching lines @@
   // so set it to 62. Even if on POSIX it could be a larger value, it usually
   // doesn't give much more information.
   static const int kMaxTraces = 62;
 
   void* trace_[kMaxTraces];
 
   // The number of valid frames in |trace_|.
   size_t count_;
 };
 
-namespace internal {
-
-#if defined(OS_POSIX) && !defined(OS_ANDROID)
-// POSIX doesn't define any async-signal safe function for converting
-// an integer to ASCII. We'll have to define our own version.
-// itoa_r() converts a (signed) integer to ASCII. It returns "buf", if the
-// conversion was successful or NULL otherwise. It never writes more than "sz"
-// bytes. Output will be truncated as needed, and a NUL character is always
-// appended.
-BASE_EXPORT char *itoa_r(intptr_t i,
-                         char *buf,
-                         size_t sz,
-                         int base,
-                         size_t padding);
-#endif  // defined(OS_POSIX) && !defined(OS_ANDROID)
-
-}  // namespace internal
-
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_STACK_TRACE_H_