Telemetry: Fix exact_matches in telemetry.test_runner.

tools/telemetry/telemetry/test_runner.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Parses the command line, discovers the appropriate tests, and runs them.
 
 Handles test configuration, but all the logic for
 actually running the test is in Test and PageRunner."""
 
 import hashlib
@@ skipping 228 matching lines @@
   if exact_matches:
     # Don't add aliases to search dict, only allow exact matching for them.
     if input_test_name in config.test_aliases:
       exact_match = config.test_aliases[input_test_name]
     else:
       exact_match = input_test_name
 
     for test_class in _Tests():
       if exact_match == test_class.Name():
         return [test_class]
+    return []
 
   # Fuzzy matching.
   return [test_class for test_class in _Tests()
           if _Matches(input_test_name, test_class.Name())]
 
 
 def _GetJsonTestList(possible_browser, test_classes, num_shards):
   """Returns a list of all enabled tests in a JSON format expected by buildbots.
 
   JSON format (see build/android/pylib/perf/test_runner.py):
@@ skipping 92 matching lines @@
 
   # Parse and run the command.
   parser = command.CreateParser()
   command.AddCommandLineArgs(parser)
   options, args = parser.parse_args()
   if commands:
     args = args[1:]
   options.positional_args = args
   command.ProcessCommandLineArgs(parser, options)
   return command().Run(options)