telemetry: Allow page tests to be configured via constructor

tools/telemetry/telemetry/page/page_test.py

Index: tools/telemetry/telemetry/page/page_test.py
diff --git a/tools/telemetry/telemetry/page/page_test.py b/tools/telemetry/telemetry/page/page_test.py
index 28282024440946b9755f4930d6df609739af779b..a92c7c1d24964daf26179f21af95f6b2ab74d160 100644
--- a/tools/telemetry/telemetry/page/page_test.py
+++ b/tools/telemetry/telemetry/page/page_test.py
@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-from telemetry.core import command_line
 from telemetry.page import test_expectations
 from telemetry.page.actions import action_runner as action_runner_module
 
@@ -23,7 +22,7 @@ class MeasurementFailure(Failure):
   designed-for problem."""
 
 
-class PageTest(command_line.Command):
+class PageTest(object):
   """A class styled on unittest.TestCase for creating page-specific tests.
 
   Test should override ValidateAndMeasurePage to perform test
@@ -98,6 +97,14 @@ class PageTest(command_line.Command):
     # _exit_requested is set to true when the test requests an early exit.
     self._exit_requested = False
 
+  def AddCommandLineArgs(self, parser):
+    """Override to accept custom command-line arguments."""
+
+  def ProcessCommandLineArgs(self, parser, args):
+    """Override to process command-line arguments.
+
+    We pass in parser so we can call parser.error()."""
+
   @classmethod
   def SetArgumentDefaults(cls, parser):
     parser.set_defaults(**cls.options)
@@ -144,11 +151,6 @@ class PageTest(command_line.Command):
   def max_failures(self, count):
     self._max_failures = count
 
-  def Run(self, args):
-    # Define this method to avoid pylint errors.
-    # TODO(dtu): Make this actually run the test with args.page_set.
-    pass
-
   def RestartBrowserBeforeEachPage(self):
     """ Should the browser be restarted for the page?