https://build.chromium.org/p/chromium.fyi/builders/Android%20ChromeDriver%20Tests%20%28dbg%29 has been failing at provision_devices with:

VPYTHON_VIRTUALENV_ROOT: /b/c/vpython
I    0.005s TimeoutThread-1-for-MainThread  [host]> /b/build/slave/Android_ChromeDriver_Tests__dbg_/build/src/third_party/android_tools/sdk/platform-tools/adb devices
E    0.069s Main  No available devices to provision.
E    0.069s Main  Local device blacklist: {u'0757a2f000599749': {u'timestamp': 1497284232.002623, u'reason': u'reboot_timeout'}}
E    0.069s Main  Unable to provision local devices.
Traceback (most recent call last):
  File "/b/build/slave/Android_ChromeDriver_Tests__dbg_/build/src/third_party/catapult/devil/devil/android/tools/provision_devices.py", line 656, in main
    wipe=not args.skip_wipe and not args.emulators)
  File "/b/build/slave/Android_ChromeDriver_Tests__dbg_/build/src/third_party/catapult/devil/devil/android/tools/provision_devices.py", line 96, in ProvisionDevices
    devices = script_common.GetDevices(devices, blacklist)
  File "/b/build/slave/Android_ChromeDriver_Tests__dbg_/build/src/third_party/catapult/devil/devil/android/tools/script_common.py", line 18, in GetDevices
    raise device_errors.NoDevicesError()
NoDevicesError: No devices attached.

https://luci-logdog.appspot.com/v/?s=chromium%2Fbb%2Fchromium.fyi%2FAndroid_ChromeDriver_Tests__dbg_%2F34502%2F%2B%2Frecipes%2Fsteps%2Fprovision_devices%2F0%2Fstdout