Update the tcmalloc chromium branch to r144 (gperftools 2.0), and merge chromium-specific changes.

third_party/tcmalloc/chromium/src/stacktrace_libunwind-inl.h

 // Copyright (c) 2005, 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
@@ skipping 27 matching lines @@
 // Anything that should only be defined once should be here:
 
 // We only need local unwinder.
 #define UNW_LOCAL_ONLY
 
 extern "C" {
 #include <assert.h>
 #include <string.h>   // for memset()
 #include <libunwind.h>
 }
-#include "google/stacktrace.h"
+#include "gperftools/stacktrace.h"
 #include "base/logging.h"
 
 // Sometimes, we can try to get a stack trace from within a stack
 // trace, because libunwind can call mmap (maybe indirectly via an
 // internal mmap based memory allocator), and that mmap gets trapped
 // and causes a stack-trace request.  If were to try to honor that
 // recursive request, we'd end up with infinite recursion or deadlock.
 // Luckily, it's safe to ignore those subsequent traces.  In such
 // cases, we return 0 to indicate the situation.
 static __thread int recursive;
@@ skipping 60 matching lines @@
     if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp) , 0) {
       break;
     }
     sizes[n - 1] = next_sp - sp;
 #endif
   }
 out:
   --recursive;
   return n;
 }