Pass in the devserver URL and board to gmerge.

For official test images, we don't include the devserver_url
in /etc/lsb-release which I was using when running this test locally.
Set these directly.

BUG=chromium:182314
TEST=Ran it (overrides took effect).

Change-Id: Ie7fafe7d7d4090484ec951258ea14584e8ab43ce
Reviewed-on: https://gerrit.chromium.org/gerrit/45221
Commit-Queue: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/devmode-test/devinstall_test.py b/devmode-test/devinstall_test.py
index af5e56a..ad9ac1f 100755
--- a/devmode-test/devinstall_test.py
+++ b/devmode-test/devinstall_test.py
@@ -142,7 +142,7 @@
       self.devserver.start()
       self.devserver.WaitUntilStarted()
       self.binhost = dev_server_wrapper.DevServerWrapper.GetDevServerURL(
-          None, 'static/pkgroot/%s/packages' % self.board)
+          sub_dir='static/pkgroot/%s/packages' % self.board)
 
     logging.info('Using binhost %s', self.binhost)
 
@@ -168,8 +168,10 @@
     """Evaluates whether the test passed or failed."""
     logging.info('Testing that gmerge works on the image after dev install.')
     try:
-      self.remote_access.RemoteSh(['gmerge', 'gmerge', '--accept_stable',
-                                   '--usepkg'])
+      self.remote_access.RemoteSh(
+          ['gmerge', 'gmerge', '--accept_stable', '--usepkg',
+           '--devserver_url', self.devserver.GetDevServerURL(),
+           '--board', self.board])
     except cros_build_lib.RunCommandError as e:
       logging.error('gmerge test failed. See log for details')
       raise TestError('gmerge test failed with: %s' % str(e))
diff --git a/lib/dev_server_wrapper.py b/lib/dev_server_wrapper.py
index 684a5f3..33032ab 100644
--- a/lib/dev_server_wrapper.py
+++ b/lib/dev_server_wrapper.py
@@ -102,7 +102,7 @@
     raise DevServerException('Timeout waiting for the devserver to startup.')
 
   @classmethod
-  def GetDevServerURL(cls, port, sub_dir):
+  def GetDevServerURL(cls, port=None, sub_dir=None):
     """Returns the dev server url for a given port and sub directory."""
     if not port: port = 8080
     url = 'http://%(ip)s:%(port)s' % {'ip': GetIPAddress(), 'port': str(port)}