Add use of Psyco to GYP on Windows. On my z600 with 12 GB of RAM,

build/gyp_chromium

Index: build/gyp_chromium
diff --git a/build/gyp_chromium b/build/gyp_chromium
index 7709d071a9b9a1a8fb420e420463f1d1517a2f89..1890d2a0cd5d813bc2ead47a0e35b800bbad850c 100755
--- a/build/gyp_chromium
+++ b/build/gyp_chromium
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 
-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 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.
 
@@ -19,6 +19,25 @@ chrome_src = os.path.normpath(os.path.join(script_dir, os.pardir))
 sys.path.insert(0, os.path.join(chrome_src, 'tools', 'gyp', 'pylib'))
 import gyp
 
+# 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).
+if sys.platform == 'win32':
+  try:
+    sys.path.insert(0, os.path.join(chrome_src, 'third_party', 'psyco_win32'))
+    import psyco
+  except:
+    psyco = None
+else:
+  psyco = None
+
 def apply_gyp_environment(file_path=None):
   """
   Reads in a *.gyp_env file and applies the valid keys to os.environ.
@@ -79,6 +98,11 @@ def additional_include_files(args=[]):
 if __name__ == '__main__':
   args = sys.argv[1:]
 
+  # 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