Make GOMA_DIR injected from env.

buildbot/buildbot_pnacl_toolchain.py

Index: buildbot/buildbot_pnacl_toolchain.py
diff --git a/buildbot/buildbot_pnacl_toolchain.py b/buildbot/buildbot_pnacl_toolchain.py
index ae1f7aca3fcd2ed97c351ca426fa0f0079fc346b..010a59d0f9a080381f061e4abaf25a23550d1964 100755
--- a/buildbot/buildbot_pnacl_toolchain.py
+++ b/buildbot/buildbot_pnacl_toolchain.py
@@ -28,7 +28,8 @@ BUILD_DIR = os.path.join(NACL_DIR, 'build')
 PACKAGE_VERSION_DIR = os.path.join(BUILD_DIR, 'package_version')
 PACKAGE_VERSION_SCRIPT = os.path.join(PACKAGE_VERSION_DIR, 'package_version.py')
 
-GOMA_PATH = '/b/build/goma'
+GOMA_DEFAULT_PATH = '/b/build/goma'
+GOMA_PATH = os.environ.get('GOMA_DIR', GOMA_DEFAULT_PATH)
 GOMA_CTL = os.path.join(GOMA_PATH, 'goma_ctl.py')
 
 # As this is a buildbot script, we want verbose logging. Note however, that
@@ -78,6 +79,9 @@ toolchain_install_dir = os.path.join(
 use_goma = (buildbot_lib.RunningOnBuildbot() and not args.no_goma
             and os.path.isfile(GOMA_CTL))
 
+# If NOCONTROL_GOMA is set, the script does not start/stop goma compiler_proxy.
+control_goma = use_goma and not os.environ.get('NOCONTROL_GOMA')
+
 
 def ToolchainBuildCmd(sync=False, extra_flags=[]):
   sync_flag = ['--sync'] if sync else []
@@ -141,7 +145,7 @@ if host_os != 'win':
          os.path.join(
              NACL_DIR, '..', 'tools', 'clang', 'scripts', 'update.py')])
 
-if use_goma:
+if control_goma:
   buildbot_lib.Command(context, cmd=[sys.executable, GOMA_CTL, 'restart'])
 
 # toolchain_build outputs its own buildbot annotations, so don't use
@@ -155,7 +159,7 @@ if use_goma:
 # First build only the packages that will be uploaded, and upload them.
 RunWithLog(ToolchainBuildCmd(sync=True, extra_flags=['--canonical-only']))
 
-if use_goma:
+if control_goma:
   buildbot_lib.Command(context, cmd=[sys.executable, GOMA_CTL, 'stop'])
 
 if args.skip_tests: