Android GN: don't reboot before running

infra/bots/recipe_modules/flavor/gn_android_flavor.py

 # Copyright 2016 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.
 
 import default_flavor
 import subprocess
 
 """GN Android flavor utils, used for building Skia for Android with GN."""
 class GNAndroidFlavorUtils(default_flavor.DefaultFlavorUtils):
   def __init__(self, m):
@@ skipping 43 matching lines @@
         'ndk': quote(self.m.vars.slave_dir.join(ndk_asset)),
         'target_cpu': quote(target_arch),
     }.iteritems()))
 
     self._run('fetch-gn', self.m.vars.skia_dir.join('bin', 'fetch-gn'),
               infra_step=True)
     self._run('gn gen', 'gn', 'gen', self.out_dir, '--args=' + gn_args)
     self._run('ninja', 'ninja', '-C', self.out_dir)
 
   def install(self):
     self._adb('reboot', 'reboot')

[borenet, 2016/09/13 17:23:25]

I recommend sleeping for at least 10s after issuing the reboot command, or the
device won't have actually gone down for reboot before wait-for-device declares
that it's back up again.

     self._adb('wait for device', 'wait-for-usb-device')
+    self.m.python.inline('wait for sys.boot_completed', """
+    import subprocess
+    import sys
+    import time

[borenet, 2016/09/13 17:23:25]

I recommend folding the "adb reboot", "sleep 10", "adb wait-for-usb-device", and
getprop stuff all into this inline script.

+    time.sleep(30)
+    for attempt in range(30):
+      done = subprocess.check_output(['adb', 'shell',
+                                      'getprop', 'sys.boot_completed'])

[borenet, 2016/09/13 17:23:25]

Might want to try/catch this in case weird things happen to the USB connection
while the device is booting.

+      if done.strip() == '1':
+        sys.exit(0)
+      time.sleep(1)
+    sys.exit(1)
+    """, infra_step=True)
     self._adb('TEMPORARY clear /data/local/tmp',
               'shell', 'rm', '-rf', '/data/local/tmp/*')
     self._adb('mkdir /data/local/tmp/resources',
               'shell', 'mkdir', '-p', '/data/local/tmp/resources')
 
   def cleanup_steps(self):
     if self._ever_ran_adb:
       self._adb('TEMPORARY clear /data/local/tmp',
                 'shell', 'rm', '-rf', '/data/local/tmp/*')
       self._adb('TEMPORARY reboot', 'reboot')
@@ skipping 50 matching lines @@
   def read_file_on_device(self, path):
     return self._adb('read %s' % path,
                      'shell', 'cat', path, stdout=self.m.raw_io.output()).stdout
 
   def remove_file_on_device(self, path):
     self._adb('rm %s' % path, 'shell', 'rm', '-f', path)
 
   def create_clean_device_dir(self, path):
     self._adb('rm %s' % path, 'shell', 'rm', '-rf', path)
     self._adb('mkdir %s' % path, 'shell', 'mkdir', '-p', path)