Add wrapper method for enabling adb root.

build/android/pylib/android_commands.py

Index: build/android/pylib/android_commands.py
diff --git a/build/android/pylib/android_commands.py b/build/android/pylib/android_commands.py
index e7a27f91228a2711679e0986d26466119a2272da..fbde91c4e05cdf299a08a2f0e72665153848f95b 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -215,6 +215,20 @@ class AndroidCommands(object):
     root_test_output = self.RunShellCommand('ls /root') or ['']
     return not 'Permission denied' in root_test_output[0]
 
+  def EnableAdbRoot(self):
+    """Enables adb root on the device.
+
+      Returns:
+        True: if output from executing adb reboot was as expected.

[bulach, 2012/09/21 10:36:46]

nit: s/reboot/root/ :)
also, I think 221-223 needs to be unindented by 1 space, i.e., Returns is
aligned with the first quote """ from 219 (see 243-249 and other blocks below..)

[shashi, 2012/09/24 18:33:28]

Oops my bad, I have a CL to fix this.
On 2012/09/21 10:36:46, bulach wrote:

+        False: otherwise.
+    """
+    return_value = self._adb.EnableAdbRoot()
+    # EnableAdbRoot inserts a call for wait-for-device only when adb logcat
+    # output matches what is expected. Just to be safe add a call to
+    # wait-for-device.
+    self._adb.SendCommand('wait-for-device')
+    return return_value
+
   def GetDeviceYear(self):
     """Returns the year information of the date on device."""
     return self.RunShellCommand('date +%Y')[0]