Implement --browser=<perf trybot>

tools/telemetry/telemetry/unittest/run_tests.py

Index: tools/telemetry/telemetry/unittest/run_tests.py
diff --git a/tools/telemetry/telemetry/unittest/run_tests.py b/tools/telemetry/telemetry/unittest/run_tests.py
index 92c2c336d826f75e26680660317e7f91b92515f7..1223e33d9dc97352aa973cf5e80259dd6d3f54cc 100644
--- a/tools/telemetry/telemetry/unittest/run_tests.py
+++ b/tools/telemetry/telemetry/unittest/run_tests.py
@@ -2,8 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import json
 import logging
+import StringIO
 import unittest
+import urllib2
 
 from telemetry import decorators
 from telemetry.core import browser_finder
@@ -110,6 +113,16 @@ def RestoreLoggingLevel(func):
 
 config = None
 
+# pylint: disable=W0613
+def stuburlopen(url):
+  assert not hasattr(stuburlopen, 'called')
+  setattr(stuburlopen, 'called', 1)
+  return StringIO.StringIO(json.dumps({'builders':{
+      'android_nexus4_perf_bisect': 'stuff',
+      'mac_10_9_perf_bisect': 'otherstuff',
+      'win_perf_bisect_builder': 'not a trybot',
+  }}))
+
 
 class RunTestsCommand(command_line.OptparseCommand):
   """Run unit tests"""
@@ -205,4 +218,5 @@ class RunTestsCommand(command_line.OptparseCommand):
   @classmethod
   @RestoreLoggingLevel
   def main(cls, args=None):
+    urllib2.urlopen = stuburlopen
     return super(RunTestsCommand, cls).main(args)

[sullivan, 2014/08/15 14:58:37]

There's one big problem with this CL: the unit tests end up invoking FindBrowser
which calls FindAllBrowserTypes() which calls
trybot_browser_finder.FindAllBrowserTypes() which pings the buildbot JSON url.

I made this ugly hack to demonstrate that decorators.Cache is working correctly:
urllib.urlopen() gets called exactly once when running all the unit tests. But
mocking out url opens for my trybot_browser_finder_unittest in run_tests is
awful. Is there a better way to do this?