Set BOTO_CONFIG correctly in cloud_storage.py

common/py_utils/py_utils/cloud_storage.py

Index: common/py_utils/py_utils/cloud_storage.py
diff --git a/common/py_utils/py_utils/cloud_storage.py b/common/py_utils/py_utils/cloud_storage.py
index 7bc9a19742587db624c2628c0eb38e89238f38ac..e2420edce598aa35217f30373e6f064b3511018a 100644
--- a/common/py_utils/py_utils/cloud_storage.py
+++ b/common/py_utils/py_utils/cloud_storage.py
@@ -50,6 +50,7 @@ _GSUTIL_PATH = os.path.join(py_utils.GetCatapultDir(), 'third_party', 'gsutil',
 # TODO(tbarzic): A workaround for http://crbug.com/386416 and
 #     http://crbug.com/359293. See |_RunCommand|.
 _CROS_GSUTIL_HOME_WAR = '/home/chromeos-test/'
+_CROS_GSUTIL_BOTO_PATH = '/home/chrome-bot/.boto'
 
 
 # If Environment variables has DISABLE_CLOUD_STORAGE_IO set to '1', any method
@@ -124,12 +125,15 @@ def _RunCommand(args):
   # which is not writable. gsutil will attempt to create a download tracker dir
   # in home dir and fail. To avoid this, override HOME dir to something writable
   # when running on cros device.
+  # We also need to set BOTO_CONFIG to point at the .boto file in the actual
+  # HOME directory.
   #
   # TODO(tbarzic): Figure out a better way to handle gsutil on cros.
   #     http://crbug.com/386416, http://crbug.com/359293.
   gsutil_env = None
   if py_utils.IsRunningOnCrosDevice():
     gsutil_env = os.environ.copy()
+    gsutil_env['BOTO_CONFIG'] = _CROS_GSUTIL_BOTO_PATH
     gsutil_env['HOME'] = _CROS_GSUTIL_HOME_WAR
 
   if os.name == 'nt':