Change CWD during cros VM tests only for remote tests.

It screws with the host cmd for host-side tests:
https://chromium-swarm.appspot.com/task?id=3ef65521090b3a10

R=jbudorick

Change-Id: If903a70eeb5f6044ee888d436cbbc56848c5a6c3
Reviewed-on: https://chromium-review.googlesource.com/1153779
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578833}

build/chromeos/run_vm_test.py

@@ -301,6 +301,10 @@ class BrowserSanityTest(RemoteTest):
 
 
 def vm_test(args, unknown_args):
+  # cros_run_vm_test has trouble with relative paths that go up directories,
+  # so cd to src/, which should be the root of all data deps.
+  os.chdir(CHROMIUM_SRC_PATH)
+
   # pylint: disable=redefined-variable-type
   # TODO: Remove the above when depot_tool's pylint is updated to include the
   # fix to https://github.com/PyCQA/pylint/issues/710.
@@ -426,10 +430,6 @@ def main():
         '/dev/kvm is not writable as current user. Perhaps you should be root?')
     return 1
 
-  # cros_run_vm_test has trouble with relative paths that go up directories, so
-  # cd to src/, which should be the root of all data deps.
-  os.chdir(CHROMIUM_SRC_PATH)
-
   args.cros_cache = os.path.abspath(args.cros_cache)
   return args.func(args, unknown_args)