diff --git a/Makefile.am b/Makefile.am
index 6fed874..ce40ecd 100755
--- a/Makefile.am
+++ b/Makefile.am
@@ -239,7 +239,6 @@ SPINLOCK_INCLUDES = src/base/spinlock.h \
                     src/base/spinlock_win32-inl.h \
                     src/base/spinlock_linux-inl.h \
                     src/base/spinlock_posix-inl.h \
-                    src/base/synchronization_profiling.h \
                     src/base/atomicops-internals-macosx.h \
                     src/base/atomicops-internals-linuxppc.h \
                     src/base/atomicops-internals-arm-generic.h \
diff --git a/src/base/spinlock.cc b/src/base/spinlock.cc
index 088785f..bee82f0 100644
--- a/src/base/spinlock.cc
+++ b/src/base/spinlock.cc
@@ -34,7 +34,6 @@
 
 #include <config.h>
 #include "base/spinlock.h"
-#include "base/synchronization_profiling.h"
 #include "base/spinlock_internal.h"
 #include "base/cycleclock.h"
 #include "base/sysinfo.h"   /* for NumCPUs() */
@@ -151,24 +150,6 @@ enum { PROFILE_TIMESTAMP_SHIFT = 7 };
 
 void SpinLock::SlowUnlock(uint64 wait_cycles) {
   base::internal::SpinLockWake(&lockword_, false);  // wake waiter if necessary
-
-  // Collect contentionz profile info, expanding the wait_cycles back out to
-  // the full value.  If wait_cycles is <= kSpinLockSleeper, then no wait
-  // was actually performed, so don't record the wait time.  Note, that the
-  // CalculateWaitCycles method adds in kSpinLockSleeper cycles
-  // unconditionally to guarantee the wait time is not kSpinLockFree or
-  // kSpinLockHeld.  The adding in of these small number of cycles may
-  // overestimate the contention by a slight amount 50% of the time.  However,
-  // if this code tried to correct for that addition by subtracting out the
-  // kSpinLockSleeper amount that would underestimate the contention slightly
-  // 50% of the time.  Both ways get the wrong answer, so the code
-  // overestimates to be more conservative. Overestimating also makes the code
-  // a little simpler.
-  //
-  if (wait_cycles > kSpinLockSleeper) {
-    base::SubmitSpinLockProfileData(this,
-                                    wait_cycles << PROFILE_TIMESTAMP_SHIFT);
-  }
 }
 
 inline int32 SpinLock::CalculateWaitCycles(int64 wait_start_time) {
diff --git a/src/base/synchronization_profiling.h b/src/base/synchronization_profiling.h
deleted file mode 100644
index b495034..0000000
--- a/src/base/synchronization_profiling.h
+++ /dev/null
@@ -1,51 +0,0 @@
-// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
-/* Copyright (c) 2010, 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
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * ---
- * Author: Chris Ruemmler
- */
-
-#ifndef BASE_AUXILIARY_SYNCHRONIZATION_PROFILING_H_
-#define BASE_AUXILIARY_SYNCHRONIZATION_PROFILING_H_
-
-#include "base/basictypes.h"
-
-namespace base {
-
-// We can do contention-profiling of SpinLocks, but the code is in
-// mutex.cc, which is not always linked in with spinlock.  Hence we
-// provide a weak definition, which are used if mutex.cc isn't linked in.
-
-// Submit the number of cycles the spinlock spent contending.
-ATTRIBUTE_WEAK extern void SubmitSpinLockProfileData(const void *, int64);
-extern void SubmitSpinLockProfileData(const void *contendedlock,
-                                      int64 wait_cycles) {}
-}
-#endif  // BASE_AUXILIARY_SYNCHRONIZATION_PROFILING_H_