Move the "import find_depot_tools" line to sections that actually use it.

build/gyp_chromium

 #!/usr/bin/env python
 
 # Copyright (c) 2012 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.
 
 # This script is wrapper for Chromium that adds some support for how GYP
 # is invoked by Chromium beyond what can be done in the gclient hooks.
 
 import glob
@@ skipping 21 matching lines @@
 sys.path.insert(1, os.path.join(chrome_src, 'tools', 'grit'))
 sys.path.insert(1, os.path.join(chrome_src, 'chrome', 'tools', 'build'))
 sys.path.insert(1, os.path.join(chrome_src, 'native_client', 'build'))
 sys.path.insert(1, os.path.join(chrome_src, 'native_client_sdk', 'src',
     'build_tools'))
 sys.path.insert(1, os.path.join(chrome_src, 'remoting', 'tools', 'build'))
 sys.path.insert(1, os.path.join(chrome_src, 'third_party', 'liblouis'))
 sys.path.insert(1, os.path.join(chrome_src, 'third_party', 'WebKit',
     'Source', 'build', 'scripts'))
 
-import find_depot_tools
-
 # On Windows, Psyco shortens warm runs of build/gyp_chromium by about
 # 20 seconds on a z600 machine with 12 GB of RAM, from 90 down to 70
 # seconds.  Conversely, memory usage of build/gyp_chromium with Psyco
 # maxes out at about 158 MB vs. 132 MB without it.
 #
 # Psyco uses native libraries, so we need to load a different
 # installation depending on which OS we are running under. It has not
 # been tested whether using Psyco on our Mac and Linux builds is worth
 # it (the GYP running time is a lot shorter, so the JIT startup cost
 # may not be worth it).
@@ skipping 320 matching lines @@
 
   # Use the Psyco JIT if available.
   if psyco:
     psyco.profile()
     print "Enabled Psyco JIT."
 
   # Fall back on hermetic python if we happen to get run under cygwin.
   # TODO(bradnelson): take this out once this issue is fixed:
   #    http://code.google.com/p/gyp/issues/detail?id=177
   if sys.platform == 'cygwin':
+    import find_depot_tools
     depot_tools_path = find_depot_tools.add_depot_tools_to_path()
     python_dir = sorted(glob.glob(os.path.join(depot_tools_path,
                                                'python2*_bin')))[-1]
     env = os.environ.copy()
     env['PATH'] = python_dir + os.pathsep + env.get('PATH', '')
     p = subprocess.Popen(
        [os.path.join(python_dir, 'python.exe')] + sys.argv,
        env=env, shell=False)
     p.communicate()
     sys.exit(p.returncode)
@@ skipping 42 matching lines @@
   if sys.platform.startswith('win') and not os.environ.get('GYP_GENERATORS'):
     os.environ['GYP_GENERATORS'] = 'ninja'
   elif sys.platform == 'darwin' and not os.environ.get('GYP_GENERATORS') and \
       not 'OS=ios' in os.environ.get('GYP_DEFINES', []):
     os.environ['GYP_GENERATORS'] = 'ninja'
 
   # If on windows, and the automatic toolchain has been installed by
   # depot_tools, then use it.
   vs2013_runtime_dll_dirs = None
   if sys.platform in ('win32', 'cygwin'):
+    import find_depot_tools
     depot_tools_path = find_depot_tools.add_depot_tools_to_path()
     toolchain = os.path.normpath(os.path.join(
         depot_tools_path, 'win_toolchain', 'vs2013_files'))
     version_file = os.path.join(toolchain, '.version')
     if os.path.isdir(toolchain) and os.path.isfile(version_file):
       os.environ['GYP_MSVS_OVERRIDE_PATH'] = toolchain
       with open(version_file, 'r') as f:
         version_is_pro = f.read().strip() == 'pro'
       vs2013_runtime_dll_dirs = (os.path.join(toolchain, 'sys32'),
                                  os.path.join(toolchain, 'sys64'))
@@ skipping 40 matching lines @@
   # rather than a separate runhooks step so that any environment modifications
   # from above are picked up.
   print 'Running build/landmines.py...'
   subprocess.check_call(
       [sys.executable, os.path.join(script_dir, 'landmines.py')])
 
   if vs2013_runtime_dll_dirs:
     CopyVsRuntimeDlls(GetOutputDirectory(), vs2013_runtime_dll_dirs)
 
   sys.exit(gyp_rc)