Revert of [Telemetry] Fix WPR files not being downloaded when required....

Revert of [Telemetry] Fix WPR files not being downloaded when required. (patchset #4 id:60001 of https://codereview.chromium.org/834173006/)

Reason for revert:
Possible suspect for newly introduced telemetry unit test flake, e.g.:

https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%29/builds/1965/steps/telemetry_unittests/logs/stdio

Reverting to see what happens.

Original issue's description:
> [Telemetry] Fix WPR files not being downloaded when required.
>
> BUG=
>
> Committed: https://crrev.com/672e7140315568e9bfc442770a23fee66e045cb2
> Cr-Commit-Position: refs/heads/master@{#311496}

TBR=nednguyen@google.com,aiolos@chromium.org,lizeb@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/852863003

Cr-Commit-Position: refs/heads/master@{#311551}

tools/telemetry/telemetry/unittest_util/system_stub.py

@@ -182,7 +182,6 @@ class CloudStorageModuleStub(object):
     self.local_file_hashes = {}
     self.local_hash_files = {}
     self.permission_level = CloudStorageModuleStub.INTERNAL_PERMISSION
-    self.downloaded_files = []
 
   def SetPermissionLevelForTesting(self, permission_level):
     self.permission_level = permission_level
@@ -261,7 +260,6 @@ class CloudStorageModuleStub(object):
     local_hash = self.local_file_hashes[local_path]
     if only_if_changed and remote_hash == local_hash:
       return False
-    self.downloaded_files.append(remote_path)
     self.local_file_hashes[local_path] = remote_hash
     self.local_hash_files[local_path + '.sha1'] = remote_hash
     return remote_hash

tools/telemetry/telemetry/wpr/archive_info.py

@@ -73,9 +73,12 @@ class WprArchiveInfo(object):
     exists.
     """
     # Download all .wpr files.
+    if self._data:
+      return
     if not self._bucket:
       logging.warning('User story set in %s has no bucket specified, and '
                       'cannot be downloaded from cloud_storage.', )
+
     for archive_path in self._data['archives']:
       archive_path = self._WprFileNameToPath(archive_path)
       try:

tools/telemetry/telemetry/wpr/archive_info_unittest.py

@@ -8,7 +8,6 @@ import tempfile
 import unittest
 
 from telemetry.page import page
-from telemetry.unittest_util import system_stub
 from telemetry.util import cloud_storage
 from telemetry.wpr import archive_info
 
@@ -60,23 +59,6 @@ class WprArchiveInfoTest(unittest.TestCase):
     with open(file_path + '.sha1', 'rb') as f:
       self.assertEquals(cloud_storage.CalculateHash(file_path), f.read())
 
-  def testDownloadArchivesIfNeeded(self):
-    overrides = system_stub.Override(archive_info, ['cloud_storage'])
-    try:
-      cloud_storage_stub = overrides.cloud_storage
-      # Second hash doesn't match, need to fetch it.
-      cloud_storage_stub.SetRemotePathsForTesting(
-          {cloud_storage.PUBLIC_BUCKET: {recording1: "dummyhash",
-                                         recording2: "dummyhash22"}})
-      cloud_storage_stub.SetCalculatedHashesForTesting(
-          {os.path.join(self.tmp_dir, recording1): "dummyhash",
-           os.path.join(self.tmp_dir, recording2): "dummyhash2",})
-      self.archive_info.DownloadArchivesIfNeeded()
-      self.assertEquals(len(cloud_storage_stub.downloaded_files), 1)
-      self.assertEquals(cloud_storage_stub.downloaded_files[0], recording2)
-    finally:
-      overrides.Restore()
-
   def testReadingArchiveInfo(self):
     self.assertIsNotNone(self.archive_info.WprFilePathForUserStory(page1))
     self.assertEquals(recording1, os.path.basename(