Fix gperftools to not arm the profiling timer by default.

third_party/tcmalloc/chromium/src/profile-handler.h

 /* Copyright (c) 2009, 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 84 matching lines @@
 
 /*
  * Registers a new thread with profile handler and should be called only once
  * per thread. The main thread is registered at program startup. This routine
  * is called by the Thread module in google3/thread whenever a new thread is
  * created. This function is not async-signal-safe.
  */
 void ProfileHandlerRegisterThread();
 
 /*
+ * Unregisters a thread before exiting. This is not strictly necessary in most
+ * cases, because the pthread library will detect that previously-valid thread
+ * identifiers have become invalid. For dead-thread detection to work, pthread
+ * identifiers are accessed even after the thread has been destroyed, which may
+ * fail in some edge cases (thread ID recycling) and even crash in exotic cases
+ * (for example, when using user-allocated stacks with NPTL and unmapping the
+ * memory after the thread terminates). Thus, it is generally good practice to
+ * call ProfileHandlerUnregisterThread() just before exiting the thread.
+ */
+void ProfileHandlerUnregisterThread();
+
+/*
  * Registers a callback routine. This callback function will be called in the
  * context of SIGPROF handler, so must be async-signal-safe. The returned token
  * is to be used when unregistering this callback via
  * ProfileHandlerUnregisterCallback. Registering the first callback enables
  * the SIGPROF signal handler. Caller must not free the returned token. This
  * function is not async-signal-safe.
  */
 ProfileHandlerToken* ProfileHandlerRegisterCallback(
     ProfileHandlerCallback callback, void* callback_arg);
 
@@ skipping 24 matching lines @@
   int64 interrupts;  /* Number of interrupts received */
   bool allowed; /* Profiling is allowed */
 };
 void ProfileHandlerGetState(struct ProfileHandlerState* state);
 
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif
 
 #endif  /* BASE_PROFILE_HANDLER_H_ */