Hard coded finch config for Popular site

components/ntp_tiles/most_visited_sites.cc

Index: components/ntp_tiles/most_visited_sites.cc
diff --git a/components/ntp_tiles/most_visited_sites.cc b/components/ntp_tiles/most_visited_sites.cc
index fab0384830af66c9f4734e5eaff4f07c9ae6be3a..047fcec1df227ed30afe07d255172f0c3cd136ad 100644
--- a/components/ntp_tiles/most_visited_sites.cc
+++ b/components/ntp_tiles/most_visited_sites.cc
@@ -9,18 +9,12 @@
 #include <string>
 #include <utility>
 
-#if defined(OS_ANDROID)
-#include <jni.h>
-#endif
-
 #include "base/callback.h"
-#include "base/command_line.h"
 #include "base/feature_list.h"
-#include "base/metrics/field_trial.h"
-#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/history/core/browser/top_sites.h"
 #include "components/ntp_tiles/constants.h"
+#include "components/ntp_tiles/field_trial.h"
 #include "components/ntp_tiles/icon_cacher.h"
 #include "components/ntp_tiles/metrics.h"
 #include "components/ntp_tiles/pref_names.h"
@@ -28,11 +22,6 @@
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
 
-#if defined(OS_ANDROID)
-#include "base/android/jni_android.h"
-#include "jni/MostVisitedSites_jni.h"
-#endif
-
 using history::TopSites;
 using suggestions::ChromeSuggestion;
 using suggestions::SuggestionsProfile;
@@ -45,30 +34,6 @@ namespace {
 const base::Feature kDisplaySuggestionsServiceTiles{
     "DisplaySuggestionsServiceTiles", base::FEATURE_ENABLED_BY_DEFAULT};
 
-bool ShouldShowPopularSites() {
-  // Note: It's important to query the field trial state first, to ensure that
-  // UMA reports the correct group.
-  const std::string group_name =
-      base::FieldTrialList::FindFullName(kPopularSitesFieldTrialName);
-
-  base::CommandLine* cmd_line = base::CommandLine::ForCurrentProcess();
-  if (cmd_line->HasSwitch(switches::kDisableNTPPopularSites))
-    return false;
-
-  if (cmd_line->HasSwitch(switches::kEnableNTPPopularSites))
-    return true;
-
-#if defined(OS_ANDROID)
-  if (Java_MostVisitedSites_isPopularSitesForceEnabled(
-          base::android::AttachCurrentThread())) {
-    return true;
-  }
-#endif
-
-  return base::StartsWith(group_name, "Enabled",
-                          base::CompareCase::INSENSITIVE_ASCII);
-}
-
 // Determine whether we need any tiles from PopularSites to fill up a grid of
 // |num_tiles| tiles.
 bool NeedPopularSites(const PrefService* prefs, int num_tiles) {
@@ -120,8 +85,8 @@ void MostVisitedSites::SetMostVisitedURLsObserver(Observer* observer,
   observer_ = observer;
   num_sites_ = num_sites;
 
-  if (popular_sites_ && ShouldShowPopularSites() &&
-      NeedPopularSites(prefs_, num_sites_)) {
+  if (popular_sites_ && NeedPopularSites(prefs_, num_sites_) &&
+      ShouldShowPopularSites()) {

[noyau (Ping after 24h), 2016/11/09 10:56:39]

I changed the order of the test, to only enroll in the experiment users who are
going to be shown popular site tiles. There is no point of counting existing
users who already have a bunch of tiles.

[rkaplow, 2016/11/10 22:56:46]

makes sense, field trial group should only be triggered IFF it will be used.

However this is a behavior change so make sure any analysis doesn't cross
version border.

[noyau (Ping after 24h), 2016/11/14 17:08:08]

Ok, I'll make sure everyone is aware.

[Marc Treib, 2016/11/16 12:50:29]

Drive-by: This is subtle and not obvious from reading the code. Could you add a
comment saying that the order matters? (Separate CL is fine)

[noyau (Ping after 24h), 2016/11/16 13:06:03]

Done.

     popular_sites_->StartFetch(
         false, base::Bind(&MostVisitedSites::OnPopularSitesAvailable,
                           base::Unretained(this)));