key_mobile_sites_smooth: Reload pages before scrolling for LinkedIn and Wowwiki

tools/perf/page_sets/key_mobile_sites_smooth.py

Index: tools/perf/page_sets/key_mobile_sites_smooth.py
diff --git a/tools/perf/page_sets/key_mobile_sites_smooth.py b/tools/perf/page_sets/key_mobile_sites_smooth.py
index 918e46ddcddf911e16e733b5e51637addf9aa090..7c09a0e30e3c2843edfbfe56c7b7fd0aa7579bfa 100644
--- a/tools/perf/page_sets/key_mobile_sites_smooth.py
+++ b/tools/perf/page_sets/key_mobile_sites_smooth.py
@@ -137,6 +137,12 @@ class KeyMobileSitesSmoothPageSet(page_set_module.PageSet):
       self.AddUserStory(
         _CreatePageClassWithSmoothInteractions(page_class)(self))
 
+    # Rerun the LinkedIn page to take the benefit of shader disk cache for
+    # gpu rasterization. Make sure the rerun is after the original page.
+    self.AddUserStory(
+      _CreatePageClassWithSmoothInteractions(
+        key_mobile_sites_pages.LinkedInPage)(self, name='LinkedIn - rerun'))
+
     # Add pages with custom page interaction logic.
 
     # Page behaves non-deterministically, replaced with test version for now.
@@ -253,8 +259,6 @@ class KeyMobileSitesSmoothPageSet(page_set_module.PageSet):
       'http://www.sfgate.com/',
       # Why: Non-latin character set
       'http://worldjournal.com/',
-      # Why: Mobile wiki
-      'http://www.wowwiki.com/World_of_Warcraft:_Mists_of_Pandaria',
       # Why: #15 Alexa news
       'http://online.wsj.com/home-page',
       # Why: Image-heavy mobile site
@@ -270,3 +274,11 @@ class KeyMobileSitesSmoothPageSet(page_set_module.PageSet):
 
     for url in urls_list:
       self.AddUserStory(KeyMobileSitesSmoothPage(url, self))
+
+    # Why: Mobile wiki
+    wow_url = 'http://www.wowwiki.com/World_of_Warcraft:_Mists_of_Pandaria'
+    self.AddUserStory(KeyMobileSitesSmoothPage(url=wow_url, page_set=self))
+    # Rerun the wowwiki page to take the benefit of shader disk cache for
+    # gpu rasterization. Make sure the rerun is after the original page.
+    self.AddUserStory(KeyMobileSitesSmoothPage(

[jdduke (slow), 2015/02/26 22:05:04]

Are we guaranteed that the same page will run on the same device? 

Would it make sense to have it done atomically, e.g., have a page that loads,
scrolls, then reloads and scrolls, and we only capture the second sequence?
Calling that the rerun?

[Yufeng Shen (Slow to review), 2015/02/26 22:15:04]

I think one benchmark always runs on the same devices. And different benchmarks
can run on different devices.
 
I was thinking of avoiding bias toward first run or second run. So I decide to
capture both.

+      url=wow_url, page_set=self, name=wow_url + ' - rerun'))