What if Chromium download fails?

Running client sync itself gives this warning.

+---------------------------------------------------------------------+
| NOTICE: This sync of Chromium will take a long time as several      |
|         gigabytes of data are downloaded. If this is your initial   |
|         sync and it's interrupted, try running 'gclient sync' again.|
|         If that fails, wipe everything clean and start over again.  |
+---------------------------------------------------------------------+
Running "gclient sync --force --revision src@316b880c55452eb694a27ba4d1aa9e74ec9ef342 -v --gclientfile .gclient.tmp --delete_unversioned_trees --reset --upstream --deps=mac,ios,mac" in /Users/rr/WebRTC/one/WebRTC/src/chromium
Looking for .gclient.tmp starting from /Users/rr/WebRTC/one/WebRTC/src/chromium

Loaded .gclient config in /Users/rr/Desktop/WebRTC/WebRTC/src/chromium:
solutions = [{
  'name': 'src',
  'url': 'https://chromium.googlesource.com/chromium/src.git',
  'deps_file': '.DEPS.git',
  'managed': False,
  'custom_deps': {
    # Skip syncing some large dependencies WebRTC will never need.
    'src/chrome/tools/test/reference_build/chrome_linux': None,
    'src/chrome/tools/test/reference_build/chrome_mac': None,
    'src/chrome/tools/test/reference_build/chrome_win': None,
    'src/native_client': None,
    'src/third_party/cld_2/src': None,
    'src/third_party/hunspell_dictionaries': None,
    'src/third_party/liblouis/src': None,
    'src/third_party/pdfium': None,
    'src/third_party/skia': None,
    'src/third_party/trace-viewer': None,
    'src/third_party/webrtc': None,
  },
  'safesync_url': ''
}]