Telemetry --device

tools/telemetry/telemetry/unittest_util/run_tests.py

Index: tools/telemetry/telemetry/unittest_util/run_tests.py
diff --git a/tools/telemetry/telemetry/unittest_util/run_tests.py b/tools/telemetry/telemetry/unittest_util/run_tests.py
index 0f3343aa83200dbd239bcf08513dfde08ac89e8a..6c92ce709d7c42048ce86df7b450a53c012b76c9 100644
--- a/tools/telemetry/telemetry/unittest_util/run_tests.py
+++ b/tools/telemetry/telemetry/unittest_util/run_tests.py
@@ -66,9 +66,14 @@ class RunTestsCommand(command_line.OptparseCommand):
       parser.error(ex)
 
     if not possible_browser:
-      parser.error('No browser found of type %s. Cannot run tests.\n'
-                   'Re-run with --browser=list to see '
-                   'available browser types.' % args.browser_type)
+      browser_on_device = ''
+      if args.device:
+        browser_on_device = args.browser_type + ' on ' + args.device
+      else:
+        browser_on_device = args.browser_type
+      parser.error('No browser found of type %s. Cannot run tests.\nRe-run with'
+                   ' --browser=list to see available browser types.'
+                   % browser_on_device)
 
   @classmethod
   def main(cls, args=None, stream=None):  # pylint: disable=W0221