Switch GYP script to not use utils.py anymore.

build/gyp_v8

Index: build/gyp_v8
diff --git a/build/gyp_v8 b/build/gyp_v8
index bf81ad34dc8860464021c128a5d07300ae342bfa..82ccdeab76e6a67955960958e4e959a35b4e0f7e 100755
--- a/build/gyp_v8
+++ b/build/gyp_v8
@@ -32,6 +32,7 @@
 
 import glob
 import os
+import platform
 import shlex
 import sys
 
@@ -43,9 +44,6 @@ if __name__ == '__main__':
   script_dir = os.path.dirname(__file__)
   v8_root = '.'
 
-sys.path.insert(0, os.path.join(v8_root, 'tools'))
-import utils
-
 sys.path.insert(0, os.path.join(v8_root, 'build', 'gyp', 'pylib'))
 import gyp
 
@@ -164,6 +162,6 @@ if __name__ == '__main__':
 
   # Generate for the architectures supported on the given platform.
   gyp_args = list(args)
-  if utils.GuessOS() == 'linux':
+  if platform.system() == 'linux':
     gyp_args.append('--generator-output=out')
   run_gyp(gyp_args)