[I-Spy] Add support for rebaselining expectations from the web UI.

chrome/test/functional/ispy/common/ispy_utils.py

 # Copyright 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.
 
-"""Utilities for managing I-Spy test results in Google Cloud Storage."""
+"""Internal utilities for managing I-Spy test results in Google Cloud Storage.
+
+See the ispy.client.chrome_utils module for the external API.
+"""
 
 import collections
 import itertools
 import json
 import os
 import sys
 
 import image_tools
 
 
@@ skipping 21 matching lines @@
   """Get the path to a failure file in the given test run and test.
 
   Args:
     test_run: name of the test run.
     expectation: name of the expectation.
     file_name: name of the file.
 
   Returns:
     the path as a string relative to the bucket.
   """
-  return 'failures/%s/%s/%s' % (test_run, expectation, file_name)
+  return GetTestRunPath(test_run, '%s/%s' % (expectation, file_name))
+
+
+def GetTestRunPath(test_run, file_name=''):
+  """Get the path to a the given test run.
+
+  Args:
+    test_run: name of the test run.
+    file_name: name of the file.
+
+  Returns:
+    the path as a string relative to the bucket.
+  """
+  return 'failures/%s/%s' % (test_run, file_name)
 
 
 class ISpyUtils(object):
   """Utility functions for working with an I-Spy google storage bucket."""
 
   def __init__(self, cloud_bucket):
     """Initialize with a cloud bucket instance to supply GS functionality.
 
     Args:
       cloud_bucket: An object implementing the cloud_bucket.BaseCloudBucket
@@ skipping 27 matching lines @@
 
   def UpdateImage(self, full_path, image):
     """Updates an existing image in GS, preserving permissions and metadata.
 
     Args:
       full_path: the path to the file in GS including the file extension.
       image: a RGB PIL.Image.
     """
     self.cloud_bucket.UpdateFile(full_path, image_tools.EncodePNG(image))
 
-
   def GenerateExpectation(self, expectation, images):
     """Creates and uploads an expectation to GS from a set of images and name.
 
     This method generates a mask from the uploaded images, then
       uploads the mask and first of the images to GS as a expectation.
 
     Args:
       expectation: name for this expectation, any existing expectation with the
         name will be replaced.
       images: a list of RGB encoded PIL.Images
@@ skipping 174 matching lines @@
 
     Args:
       prefix: the prefix to filter files in GS by.
 
     Returns:
       a list containing urls to all objects that started with
          the prefix.
     """
     return self.cloud_bucket.GetAllPaths(prefix)