Enable Popular Sites in Android demo mode.

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 236ad773be75d2115c55005df7537931612c60dc..ee951a3322c47d90916834030913710b0b197ef5 100644
--- a/components/ntp_tiles/most_visited_sites.cc
+++ b/components/ntp_tiles/most_visited_sites.cc
@@ -9,6 +9,10 @@
 #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"
@@ -27,6 +31,11 @@
 #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;
@@ -66,11 +75,21 @@ bool ShouldShowPopularSites() {
   // 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);
 }
@@ -166,6 +185,13 @@ MostVisitedSites::~MostVisitedSites() {
   supervisor_->SetObserver(nullptr);
 }
 
+#if defined(OS_ANDROID)
+// static
+bool MostVisitedSites::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+#endif
+
 void MostVisitedSites::SetMostVisitedURLsObserver(Observer* observer,
                                                   int num_sites) {
   DCHECK(observer);