Enabled PyAuto on the Mac 10.6 bots.

SConstruct

Index: SConstruct
diff --git a/SConstruct b/SConstruct
index d318edc9df15022ccb3d7cef976c392c4bd1030f..d4e947a5c3d1044d3455fa4719920a132df9555f 100755
--- a/SConstruct
+++ b/SConstruct
@@ -1291,9 +1291,11 @@ pre_base_env.AddMethod(PyAutoTester)
 # Chrome bots (because PyAuto is not expected to be available on them) and when
 # 32-bit test binaries are run on a 64-bit machine (because 32-bit python is not
 # available on 64-bit machines).
+# However, Macs will have 32-bit versions of Python 2.5, so we should be OK.

[Mark Seaborn, 2011/07/26 23:38:47]

Are you sure this will actually enable the test on OS X 10.6?

hydric:~ mseaborn$ python -c 'import platform; print platform.architecture()'
('64bit', '')

The env var VERSIONER_PYTHON_PREFER_32_BIT is supposed to work but I've not got
it to work.

"arch -arch i386 python" should work.  See
native_client/src/trusted/python_bindings/build.scons.

However, IIRC platform.architecture() can be wrong, because it checks the
executable, which is fat (multiarch) on Mac OS X 10.6.

 def PyAutoTesterIsBroken(env):
   return (PPAPIBrowserTesterIsBroken(env) or
-          (env.Bit('build_x86_32') and platform.architecture()[0] == '64bit'))
+          (env.Bit('build_x86_32') and platform.architecture()[0] == '64bit')
+          and not env.Bit('host_mac'))
 
 pre_base_env.AddMethod(PyAutoTesterIsBroken)