[telemetry] Move stale .pyc check from Python import to gclient hook.

tools/telemetry/telemetry/util/global_hooks.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Hooks that apply globally to all scripts that import or use Telemetry."""
 
-import os
 import signal
 import sys
 
-from telemetry.core import util
 from telemetry.util import exception_formatter
 
 
 def InstallHooks():
-  RemoveAllStalePycFiles(util.GetTelemetryDir())
-  RemoveAllStalePycFiles(util.GetBaseDir())
   InstallUnhandledExceptionFormatter()
   InstallStackDumpOnSigusr1()
   InstallTerminationHook()
 
 
-def RemoveAllStalePycFiles(base_dir):
-  """Scan directories for old .pyc files without a .py file and delete them."""
-  for dirname, _, filenames in os.walk(base_dir):
-    if '.svn' in dirname or '.git' in dirname:
-      continue
-    for filename in filenames:
-      root, ext = os.path.splitext(filename)
-      if ext != '.pyc':
-        continue
-
-      pyc_path = os.path.join(dirname, filename)
-      py_path = os.path.join(dirname, root + '.py')
-
-      try:
-        if not os.path.exists(py_path):
-          os.remove(pyc_path)
-      except OSError:
-        # Wrap OS calls in try/except in case another process touched this file.
-        pass
-
-    try:
-      os.removedirs(dirname)
-    except OSError:
-      # Wrap OS calls in try/except in case another process touched this dir.
-      pass
-
-
 def InstallUnhandledExceptionFormatter():
   """Print prettier exceptions that also contain the stack frame's locals."""
   sys.excepthook = exception_formatter.PrintFormattedException
 
 
 def InstallStackDumpOnSigusr1():
   """Catch SIGUSR1 and print a stack trace."""
   # Windows doesn't define SIGUSR1.
   if not hasattr(signal, 'SIGUSR1'):
     return
 
   def PrintDiagnostics(_, stack_frame):
     exception_string = 'SIGUSR1 received, printed stack trace'
     exception_formatter.PrintFormattedFrame(stack_frame, exception_string)
   signal.signal(signal.SIGUSR1, PrintDiagnostics)
 
 
 def InstallTerminationHook():
   """Catch SIGTERM, print a stack trace, and exit."""
   def PrintStackAndExit(sig, stack_frame):
     exception_string = 'Received signal %s, exiting' % sig
     exception_formatter.PrintFormattedFrame(stack_frame, exception_string)
     sys.exit(-1)
   signal.signal(signal.SIGTERM, PrintStackAndExit)