Add options to GPU pixel test to use cloud storage for reference and error images.

tools/telemetry/telemetry/page/cloud_storage.py

 # Copyright (c) 2013 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.
 
 """Wrappers for gsutil, for basic interaction with Google Cloud Storage."""
 
 import cStringIO
 import hashlib
 import logging
 import os
@@ skipping 91 matching lines @@
       raise NotFoundError(stderr)
     raise CloudStorageError(stderr)
 
   return stdout
 
 
 def List(bucket):
   stdout = _RunCommand(['ls', 'gs://%s' % bucket])
   return [url.split('/')[-1] for url in stdout.splitlines()]
 
+def Exists(bucket, remote_path):
+  try:
+    _RunCommand(['ls', 'gs://%s/%s' % (bucket, remote_path)])
+    return True
+  except NotFoundError:
+    return False
 
 def Delete(bucket, remote_path):
   url = 'gs://%s/%s' % (bucket, remote_path)
   logging.info('Deleting %s' % url)
   _RunCommand(['rm', url])
 
 
 def Get(bucket, remote_path, local_path):
   url = 'gs://%s/%s' % (bucket, remote_path)
   logging.info('Downloading %s to %s' % (url, local_path))
   _RunCommand(['cp', url, local_path])
 
 
-def Insert(bucket, remote_path, local_path):
+def Insert(bucket, remote_path, local_path, publicly_readable=False):
   url = 'gs://%s/%s' % (bucket, remote_path)
-  logging.info('Uploading %s to %s' % (local_path, url))
-  _RunCommand(['cp', local_path, url])
+  command_and_args = ['cp']
+  extra_info = ''
+  if publicly_readable:
+    command_and_args += ['-a', 'public-read']
+    extra_info = ' (publicly readable)'
+  command_and_args += [local_path, url]
+  logging.info('Uploading %s to %s%s' % (local_path, url, extra_info))
+  _RunCommand(command_and_args)
 
 
 def GetIfChanged(bucket, file_path):
   """Gets the file at file_path if it has a hash file that doesn't match.
 
   If the file is not in Cloud Storage, log a warning instead of raising an
   exception. We assume that the user just hasn't uploaded the file yet.
 
   Returns:
     True if the binary was changed.
@@ skipping 20 matching lines @@
   """Calculates and returns the hash of the file at file_path."""
   sha1 = hashlib.sha1()
   with open(file_path, 'rb') as f:
     while True:
       # Read in 1mb chunks, so it doesn't all have to be loaded into memory.
       chunk = f.read(1024*1024)
       if not chunk:
         break
       sha1.update(chunk)
   return sha1.hexdigest()