[NOT TO COMMIT!] Merge Chromium-specific changes in tcmalloc thru. the original gperftools r136.

third_party/tcmalloc/chromium/src/base/sysinfo.cc

Index: third_party/tcmalloc/chromium/src/base/sysinfo.cc
diff --git a/third_party/tcmalloc/chromium/src/base/sysinfo.cc b/third_party/tcmalloc/chromium/src/base/sysinfo.cc
index 2559158b9db2585bb816e3019c429243eb7093ea..3a1873eaf78bca92c3e2b9e766e253089584b0b6 100644
--- a/third_party/tcmalloc/chromium/src/base/sysinfo.cc
+++ b/third_party/tcmalloc/chromium/src/base/sysinfo.cc
@@ -187,6 +187,9 @@ const char* GetenvBeforeMain(const char* name) {
 // in their first character!  If that assumption is violated, we'll
 // still get a profile, but one with an unexpected name.
 // TODO(csilvers): set an envvar instead when we can do it reliably.
+//
+// In Chromium this hack is intentionally disabled, because the path is not
+// re-initialized upon fork.
 bool GetUniquePathFromEnv(const char* env_name, char* path) {
   char* envval = getenv(env_name);
   if (envval == NULL || *envval == '\0')
@@ -196,7 +199,9 @@ bool GetUniquePathFromEnv(const char* env_name, char* path) {
              envval[0] & 127, envval+1, (unsigned int)(getpid()));
   } else {
     snprintf(path, PATH_MAX, "%s", envval);
+#if 0
     envval[0] |= 128;                     // set high bit for kids to see
+#endif
   }
   return true;
 }