Change provision_devices.py to disable verity for remove webview on M

build/android/provision_devices.py

 #!/usr/bin/env python
 #
 # Copyright (c) 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.
 
 """Provisions Android devices with settings required for bots.
 
 Usage:
   ./provision_devices.py [-d <device serial number>]
@@ skipping 277 matching lines @@
   if options.disable_network:
     device_settings.ConfigureContentSettings(
         device, device_settings.NETWORK_DISABLED_SETTINGS)
 
   if options.disable_system_chrome:
     # The system chrome version on the device interferes with some tests.
     device.RunShellCommand(['pm', 'disable', 'com.android.chrome'],
                            check_return=True)
 
   if options.remove_system_webview:
+    webview_removed = False
+    for p in _SYSTEM_WEBVIEW_PATHS:
+      output = device.RunShellCommand(['ls', p], check_return=False,

[jbudorick, 2016/05/10 21:52:44]

Use DeviceUtils.PathExists:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/catapu...

[Yoland Yan(Google), 2016/05/10 22:19:20]

Done.

+                                      raw_output=True)
+      if 'No such file or directory' in output:
+        webview_removed = True
+      else:
+        webview_removed = False
+        break
+    if webview_removed:
+      logging.info('WebView already removed')
+      return

[jbudorick, 2016/05/10 21:52:44]

This shouldn't return. It should simply skip the removal below.

[Yoland Yan(Google), 2016/05/10 22:19:20]

Done.

     if device.HasRoot():
+      # Disabled Marshmallow's Verity security feature
+      if device.build_version_sdk >= version_codes.MARSHMALLOW:
+        device.adb.DisableVerity()
+        device.Reboot()
+        device.WaitUntilFullyBooted()
+        device.EnableRoot()
       # This is required, e.g., to replace the system webview on a device.
       device.adb.Remount()
       device.RunShellCommand(['stop'], check_return=True)
       device.RunShellCommand(['rm', '-rf'] + _SYSTEM_WEBVIEW_PATHS,
                              check_return=True)
       device.RunShellCommand(['start'], check_return=True)
     else:
       logging.warning('Cannot remove system webview from a non-rooted device')
 
   # Some device types can momentarily disappear after setting properties.
@@ skipping 227 matching lines @@
       },
     }
 
   devil_chromium.Initialize(custom_deps=devil_custom_deps)
 
   return ProvisionDevices(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())