Move profile handling code to a child class of SharedPageState

tools/perf/page_sets/pregenerated_large_profile_shared_state.py

 # Copyright 2015 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.
 import os
 
-from telemetry.page import shared_page_state
+from page_sets import pregenerated_profile_shared_state
 
 
-class PregeneratedLargeProfileSharedState(shared_page_state.SharedPageState):
+class PregeneratedLargeProfileSharedState(
+    pregenerated_profile_shared_state.PregeneratedProfileSharedState):
   def __init__(self, test, finder_options, story_set):
     super(PregeneratedLargeProfileSharedState, self).__init__(
         test, finder_options, story_set)
     perf_dir = os.path.normpath(
         os.path.join(os.path.dirname(__file__), os.path.pardir))
-    profile_archive_dir = os.path.join(
+    self._pregenerated_profile_archive_dir = os.path.join(
         perf_dir, 'generated_profiles', self._possible_browser.target_os,
         'large_profile.zip')
-
-    self.SetPregeneratedProfileArchiveDir(profile_archive_dir)