Added `cros_pin` CrOS pin-bump tool.

infra/tools/cros_pin/execute.py

Index: infra/tools/cros_pin/execute.py
diff --git a/infra/tools/cros_pin/execute.py b/infra/tools/cros_pin/execute.py
new file mode 100644
index 0000000000000000000000000000000000000000..ccacbefb38765ca48241c883af80301abfa1217e
--- /dev/null
+++ b/infra/tools/cros_pin/execute.py
@@ -0,0 +1,36 @@
+# Copyright 2015 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.
+
+import os
+import subprocess
+
+from infra.tools.cros_pin.logger import LOGGER
+
+
+def call(cmd, cwd=None, dry_run=False):
+  LOGGER.info("Executing command %s (cwd=%s)", cmd, (cwd or os.getcwd()))
+  if dry_run:
+    LOGGER.info('Dry Run: Not actually executing.')
+    return (0, "")
+
+  output = []
+  proc = subprocess.Popen(
+      cmd,
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT,
+      cwd=cwd)
+
+  for line in iter(proc.stdout.readline, b''):
+    LOGGER.debug('[%s]: %s', cmd[0], line.rstrip())
+    output.append(line)
+  proc.wait()
+
+  return proc.returncode, ''.join(output)
+
+
+def check_call(cmd, **kwargs):
+  rv, stdout = call(cmd, **kwargs)
+  if rv != 0:
+    raise subprocess.CalledProcessError(rv, cmd, None)
+  return stdout