Fixes dispatch files to return exit codes in several places

build/android/pylib/browsertests/dispatch.py

Index: build/android/pylib/browsertests/dispatch.py
diff --git a/build/android/pylib/browsertests/dispatch.py b/build/android/pylib/browsertests/dispatch.py
index 3867dc3a18dfd1c22b89085b59a1fa23d646371d..1c8cfb4e8c7291d717a3c73094ccc04f09fdbff3 100644
--- a/build/android/pylib/browsertests/dispatch.py
+++ b/build/android/pylib/browsertests/dispatch.py
@@ -12,6 +12,7 @@ from pylib import android_commands
 from pylib import cmd_helper
 from pylib import constants
 from pylib import ports
+from pylib.base import base_test_result
 from pylib.base import shard
 from pylib.gtest import dispatch as gtest_dispatch
 from pylib.gtest import test_runner
@@ -41,7 +42,7 @@ def Dispatch(options):
 
   if not attached_devices:
     logging.critical('A device must be attached and online.')
-    return 1
+    return (base_test_result.TestRunResults(), constants.ERROR_EXIT_CODE)
 
   # Reset the test port allocation. It's important to do it before starting
   # to dispatch any tests.