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

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 119 matching lines @@
 void ProfileHandlerReset();
 
 /*
  * Stores profile handler's current state. This function is not
  * async-signal-safe.
  */
 struct ProfileHandlerState {
   int32 frequency;  /* Profiling frequency */
   int32 callback_count;  /* Number of callbacks registered */
   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_ */