deploy_chrome: Deprecate '--to' and replace it with '--device'.

The "--device" arg is more common for tools & tests, and deploy_chrome
appears to be the only script that uses "--to" instead of "--device".

So this adds support for "--device" and prints a warning if "--to" is
used.

BUG=chromium:1115724
TEST=deploy_chrome --to localhost --port 9222
TEST=deploy_chrome --device localhost:9222

Change-Id: I4714ffb9d7833d6b586e3f5aa2dfeaf11301a51e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2347391
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Tested-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
diff --git a/scripts/deploy_chrome_unittest.py b/scripts/deploy_chrome_unittest.py
index fd5664d..d390fe3 100644
--- a/scripts/deploy_chrome_unittest.py
+++ b/scripts/deploy_chrome_unittest.py
@@ -67,6 +67,12 @@
     argv = ['--board', _TARGET_BOARD, '--gs-path', _GS_PATH]
     self.assertParseError(argv)
 
+  def testToAndDevice(self):
+    """Test no target specified."""
+    argv = ['--board', _TARGET_BOARD, '--build-dir', '/path/to/nowhere',
+            '--to', 'localhost', '--device', 'localhost']
+    self.assertParseError(argv)
+
   def testLacros(self):
     """Test basic lacros invocation."""
     argv = ['--lacros', '--nostrip', '--build-dir', '/path/to/nowhere',