[Telemetry] Remove session_restore's use of PageTest.CanRunForPage.

tools/perf/benchmarks/session_restore.py

Index: tools/perf/benchmarks/session_restore.py
diff --git a/tools/perf/benchmarks/session_restore.py b/tools/perf/benchmarks/session_restore.py
index 2591c0bc249876f059a4c2a0a84f7b94ec5dd3fb..2b6b2dc716b1add6732efbf617f2a75675490998 100644
--- a/tools/perf/benchmarks/session_restore.py
+++ b/tools/perf/benchmarks/session_restore.py
@@ -13,6 +13,12 @@ from telemetry.page import profile_generator
 
 
 class _SessionRestoreTest(benchmark.Benchmark):
+  """Create a session restore test that is either "warm" or "cold".

[qyearsley, 2015/01/28 19:39:08]

1. Possible alternative phrasing: "Base Benchmark class for session restore
benchmarks."

2. Could be re-named _SesssionRestoreTypical25 since the page set is now set in
the base class.

What is done before measurement in a "warm" test? Is it that the browser is
launched and a session restore is done first, then the tabs are closed without
closing the browser, and the session is restored again?

[slamm, 2015/02/23 23:46:35]

Done.

+
+  Use Typical25PageSet to match what the SmallProfileCreator uses.
+  TODO(slamm): Make SmallProfileCreator and this use the same page_set ref.
+  """
+  page_set = page_sets.Typical25PageSet
 
   @classmethod
   def ProcessCommandLineArgs(cls, parser, args):
@@ -34,6 +40,18 @@ class _SessionRestoreTest(benchmark.Benchmark):
             small_profile_creator.SmallProfileCreator, profile_type, new_args)
       args.browser_options.profile_dir = profile_dir
 
+  def CreateUserStorySet(self, _):
+    """Return a user story set that only has the first user story.
+
+    The session restore measurement skips the navigation step and
+    only tests session restore by having the browser start-up.
+    The first user story is used to get WPR set up and hold results.
+    """
+    user_story_set = self.page_set()
+    for user_story in user_story_set.user_stories[1:]:
+      user_story_set.RemoveUserStory(user_story)
+    return user_story_set
+
   def CreatePageTest(self, options):
     is_cold = (self.tag == 'cold')
     return session_restore.SessionRestore(cold=is_cold)
@@ -42,7 +60,6 @@ class _SessionRestoreTest(benchmark.Benchmark):
 @benchmark.Disabled('android', 'linux', 'reference')
 class SessionRestoreColdTypical25(_SessionRestoreTest):
   tag = 'cold'
-  page_set = page_sets.Typical25PageSet
   options = {'pageset_repeat': 5}
 
 
@@ -50,5 +67,4 @@ class SessionRestoreColdTypical25(_SessionRestoreTest):
 @benchmark.Disabled('android', 'linux', 'reference')
 class SessionRestoreWarmTypical25(_SessionRestoreTest):
   tag = 'warm'
-  page_set = page_sets.Typical25PageSet
   options = {'pageset_repeat': 20}