Parallelize run_corpus_tests.py.

testing/tools/common.py

Index: testing/tools/common.py
diff --git a/testing/tools/common.py b/testing/tools/common.py
index 14745a8a3e62348254e111d9999a35eec3a0ceaf..d45404b4d4dd2a3f7d7094ab903002efa0d411e0 100755
--- a/testing/tools/common.py
+++ b/testing/tools/common.py
@@ -4,6 +4,7 @@
 # found in the LICENSE file.
 
 import os
+import subprocess
 import sys
 
 def os_name():
@@ -16,6 +17,17 @@ def os_name():
   raise Exception('Confused, can not determine OS, aborting.')
 
 
+def RunCommand(cmd, redirect_output=False):
+  try:
+    if redirect_output:
+      sys.stdout.write(subprocess.check_output(cmd, stderr=subprocess.STDOUT))
+    else:
+      subprocess.check_call(cmd)
+    return None
+  except subprocess.CalledProcessError as e:
+    return e
+
+
 class DirectoryFinder:
   '''A class for finding directories and paths under either a standalone
   checkout or a chromium checkout of PDFium.'''