[Telemetry] Add a profiler based loading measurement.

tools/telemetry/telemetry/page/page_runner.py

Index: tools/telemetry/telemetry/page/page_runner.py
diff --git a/tools/telemetry/telemetry/page/page_runner.py b/tools/telemetry/telemetry/page/page_runner.py
index 23558750986a3b36b7a25e96ae3905e67c479eec..d28a8a42c8a52aa2382a362e4b6e07a09c1f6862 100644
--- a/tools/telemetry/telemetry/page/page_runner.py
+++ b/tools/telemetry/telemetry/page/page_runner.py
@@ -1,6 +1,7 @@
 # Copyright (c) 2012 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 collections
 import glob
 import logging
 import os
@@ -27,7 +28,7 @@ class _RunState(object):
     self._append_to_existing_wpr = False
     self._last_archive_path = None
     self._first_browser = True
-    self.first_page = True
+    self.first_page = collections.defaultdict(lambda: True)
     self.profiler_dir = None
 
   def StartBrowser(self, test, page_set, page, possible_browser,
@@ -69,8 +70,8 @@ class _RunState(object):
     if not self.tab:
       self.tab = self.browser.tabs[0]
 
-    if self.first_page:
-      self.first_page = False
+    if self.first_page[page]:

[nduca, 2013/07/23 06:01:27]

can dtu look at this? this seems to change the semantics of the first_page quite
a bit...

[tonyg, 2013/07/23 18:41:21]

My understanding is that this was added for the startup test and that is still
the only user. The startup test runs with the blank_page.json page set which
only consists of a single page. So an implementation that skips only the first
page is equivalent to one that skips the first cycle of each page in the page
set.

It seems more correct to me for an option called "discard_first_results" to
discard the first run of each page in the page set, not just the first run.

Please let me know if you disagree.

In the meantime I updated the test case to cover this.

[dtu, 2013/07/23 20:09:43]

Yeah, StartupWarm is the only user and will be the same either way, so whatever
you decide here is fine.

This also affects WillRunPageSet, but edmundyan's patch moved it somewhere else
entirely so we good.
https://chromiumcodereview.appspot.com/18261009/

+      self.first_page[page] = False
       test.WillRunPageSet(self.tab)
 
   def StopBrowser(self):
@@ -93,7 +94,7 @@ class _RunState(object):
     output_file = os.path.join(self.profiler_dir, page.url_as_file_safe_name)
     if options.page_repeat != 1 or options.pageset_repeat != 1:
       output_file = _GetSequentialFileName(output_file)
-    self.browser.StartProfiling(options, output_file)
+    self.browser.StartProfiling(options.profiler, output_file)
 
   def StopProfiling(self):
     self.browser.StopProfiling()
@@ -183,7 +184,7 @@ def Run(test, page_set, options):
         else:
           possible_browser.options.wpr_mode = wpr_modes.WPR_OFF
       results_for_current_run = results
-      if state.first_page and test.discard_first_result:
+      if state.first_page[page] and test.discard_first_result:
         # If discarding results, substitute a dummy object.
         results_for_current_run = type(results)()
       results_for_current_run.StartTest(page)