provide static popular sites for first run

components/ntp_tiles/popular_sites_impl.cc

Index: components/ntp_tiles/popular_sites_impl.cc
diff --git a/components/ntp_tiles/popular_sites_impl.cc b/components/ntp_tiles/popular_sites_impl.cc
index ce69227f271e9376aba9c43dd4b9217778926d26..f5cf7fb085d94ca7962916f819db044c36aded1c 100644
--- a/components/ntp_tiles/popular_sites_impl.cc
+++ b/components/ntp_tiles/popular_sites_impl.cc
@@ -11,6 +11,7 @@
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
+#include "base/json/json_reader.h"
 #include "base/path_service.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -18,6 +19,7 @@
 #include "base/values.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/google/core/browser/google_util.h"
+#include "components/grit/components_resources.h"
 #include "components/ntp_tiles/constants.h"
 #include "components/ntp_tiles/pref_names.h"
 #include "components/ntp_tiles/switches.h"
@@ -29,6 +31,7 @@
 #include "components/variations/variations_associated_data.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_status_code.h"
+#include "ui/base/resource/resource_bundle.h"
 
 #if defined(OS_IOS)
 #include "components/ntp_tiles/country_code_ios.h"
@@ -125,6 +128,27 @@ PopularSites::SitesVector ParseSiteList(const base::ListValue& list) {
   return sites;
 }
 
+PopularSites::SitesVector GetDefaultFromPrefs(const PrefService& prefs) {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(ntp_tiles::switches::kDisableNTPPopularSites)) {

[sfiera, 2017/02/13 10:58:01]

This check is not sufficient; use field_trial.h.

Also, it's better to make this check in
MostVisitedSites::CreatePopularSitesTiles(), because if the user doesn't need
popular sites (they already have enough personalized tiles), we don't even want
to check if they're needed. Checking Finch could opt them into an experimental
or control group, and they're not really either.

[fhorschig, 2017/02/13 14:57:00]

Done.
Okay, I checked it there, too. But the check here has to remain.
For some reason, the most_visited_unittests wants to instantiate
this class without registering any prefs (which can not happen).

[sfiera, 2017/02/13 15:05:54]

If the test is going to instantiate the class, it should register the prefs too.

[fhorschig, 2017/02/13 18:13:44]

Done.

+    return PopularSites::SitesVector();
+  }
+  return ParseSiteList(*prefs.GetList(kPopularSitesJsonPref));
+}
+
+// Creates the List of popular sites based on a snapshot available for mobile.
+std::unique_ptr<base::ListValue> DefaultPopularSites() {
+#if defined(OS_IOS) || defined(OS_ANDROID)

[sfiera, 2017/02/13 10:58:01]

Alphabetically, Android is before iOS. Just sayin'.

[fhorschig, 2017/02/13 14:57:00]

Done.

+  std::unique_ptr<base::ListValue> sites =
+      base::ListValue::From(base::JSONReader().ReadToValue(
+          ResourceBundle::GetSharedInstance().GetRawDataResource(
+              IDR_DEFAULT_POPULAR_SITES_JSON)));
+  DCHECK(sites);
+  return sites;
+#endif
+  return base::MakeUnique<base::ListValue>();
+}
+
 }  // namespace
 
 PopularSites::Site::Site(const base::string16& title,
@@ -158,6 +182,7 @@ PopularSitesImpl::PopularSitesImpl(
       download_context_(download_context),
       parse_json_(std::move(parse_json)),
       is_fallback_(false),
+      sites_(GetDefaultFromPrefs(*prefs_)),
       weak_ptr_factory_(this) {
   // If valid path provided, remove local files created by older versions.
   if (!directory.empty() && blocking_runner_) {
@@ -194,17 +219,7 @@ bool PopularSitesImpl::MaybeStartFetch(bool force_download,
     FetchPopularSites();
     return true;
   }
-
-  const base::ListValue* json = prefs_->GetList(kPopularSitesJsonPref);
-  if (!json) {
-    // Cache didn't exist.
-    FetchPopularSites();
-    return true;
-  } else {
-    // Note that we don't run the callback.
-    sites_ = ParseSiteList(*json);
-    return false;
-  }
+  return false;
 }
 
 const PopularSites::SitesVector& PopularSitesImpl::sites() const {
@@ -289,7 +304,8 @@ void PopularSitesImpl::RegisterProfilePrefs(
 
   user_prefs->RegisterInt64Pref(kPopularSitesLastDownloadPref, 0);
   user_prefs->RegisterStringPref(kPopularSitesURLPref, std::string());
-  user_prefs->RegisterListPref(kPopularSitesJsonPref);
+  user_prefs->RegisterListPref(kPopularSitesJsonPref,
+                               DefaultPopularSites().release());
 }
 
 void PopularSitesImpl::FetchPopularSites() {