Revert of telemetry: Remove command line args from page test

tools/perf/measurements/startup.py

Index: tools/perf/measurements/startup.py
diff --git a/tools/perf/measurements/startup.py b/tools/perf/measurements/startup.py
index bc0617d593f6e07930fdcf87fba1d247b7a3b6ad..6d26ee92a1a1b00e43ea42752d15bb2a18366dd9 100644
--- a/tools/perf/measurements/startup.py
+++ b/tools/perf/measurements/startup.py
@@ -9,16 +9,30 @@
 class Startup(page_test.PageTest):
   """Performs a measurement of Chromium's startup performance.
 
-  Uses cold start if cold==True, otherwise uses warm start. A cold start means
-  none of the Chromium files are in the disk cache. A warm start assumes the OS
-  has already cached much of Chromium's content. For warm tests, you should
-  repeat the page set to ensure it's cached.
+  This test must be invoked with either --warm or --cold on the command line. A
+  cold start means none of the Chromium files are in the disk cache. A warm
+  start assumes the OS has already cached much of Chromium's content. For warm
+  tests, you should repeat the page set to ensure it's cached.
   """
 
-  def __init__(self, cold=False, action_name_to_run=''):
+  def __init__(self, action_name_to_run = ''):
     super(Startup, self).__init__(needs_browser_restart_after_each_page=True,
                                   action_name_to_run=action_name_to_run)
-    self._cold = cold
+
+  @classmethod
+  def AddCommandLineArgs(cls, parser):
+    parser.add_option('--cold', action='store_true',
+                      help='Clear the OS disk cache before performing the test')
+    parser.add_option('--warm', action='store_true',
+                      help='Start up with everything already cached')
+
+  @classmethod
+  def ProcessCommandLineArgs(cls, parser, args):
+    cls._cold = args.cold
+    # TODO: Once the bots start running benchmarks, enforce that either --warm
+    # or --cold is explicitly specified.
+    # if args.warm == args.cold:
+    #   parser.error('You must specify either --warm or --cold')
 
   def CustomizeBrowserOptions(self, options):
     if self._cold:
@@ -41,15 +55,14 @@
 class StartWithUrl(Startup):
   """Performs a measurement of Chromium's performance starting with a URL.
 
-  Uses cold start if cold==True, otherwise uses warm start. A cold start means
-  none of the Chromium files are in the disk cache. A warm start assumes the OS
-  has already cached much of Chromium's content. For warm tests, you should
-  repeat the page set to ensure it's cached.
+  This test must be invoked with either --warm or --cold on the command line. A
+  cold start means none of the Chromium files are in the disk cache. A warm
+  start assumes the OS has already cached much of Chromium's content. For warm
+  tests, you should repeat the page set to ensure it's cached.
 
   The startup URL is taken from the page set's startup_url. This
   allows the testing of multiple different URLs in a single benchmark.
   """
 
-  def __init__(self, cold=False):
-    super(StartWithUrl, self).__init__(cold=cold,
-                                       action_name_to_run='RunNavigateSteps')
+  def __init__(self):
+    super(StartWithUrl, self).__init__(action_name_to_run='RunNavigateSteps')