Chrome should use GCM for invalidations by default.

Now that invalidations over GCM are enabled for all users it is time to
make that default. With this change Chrome will use GCM for
invalidations and only switch to XMPP explicitly as a result of sync
experiment setting.

BUG=422374
R=zea@chromium.org

Review URL: https://codereview.chromium.org/654643004

Cr-Commit-Position: refs/heads/master@{#299525}

4 files changed, 17 insertions, 21 deletions

diff --git a/chrome/browser/invalidation/profile_invalidation_provider_factory.cc b/chrome/browser/invalidation/profile_invalidation_provider_factory.cc
index bba9b33..336c830 100644
--- a/chrome/browser/invalidation/profile_invalidation_provider_factory.cc
+++ b/chrome/browser/invalidation/profile_invalidation_provider_factory.cc
@@ -141,7 +141,7 @@ void ProfileInvalidationProviderFactory::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
       prefs::kInvalidationServiceUseGCMChannel,
-      false,
+      true,  // if no value in prefs, use GCM channel.
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   InvalidatorStorage::RegisterProfilePrefs(registry);
 }
diff --git a/chrome/browser/invalidation/ticl_profile_settings_provider_unittest.cc b/chrome/browser/invalidation/ticl_profile_settings_provider_unittest.cc
index 508c120..5522ae9 100644
--- a/chrome/browser/invalidation/ticl_profile_settings_provider_unittest.cc
+++ b/chrome/browser/invalidation/ticl_profile_settings_provider_unittest.cc
@@ -73,39 +73,34 @@ TiclProfileSettingsProviderTest::GetNetworkChannel() {
 }
 
 TEST_F(TiclProfileSettingsProviderTest, ChannelSelectionTest) {
-  EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
+  // Default value should be GCM channel.
+  EXPECT_EQ(TiclInvalidationService::GCM_NETWORK_CHANNEL, GetNetworkChannel());
   PrefService* prefs =  profile_.GetPrefs();
 
-  // If stars align, use GCM channel.
+  // If GCM is enabled and invalidation channel setting is not set or set to
+  // true then use GCM channel.
   prefs->SetBoolean(prefs::kGCMChannelEnabled, true);
   prefs->SetBoolean(prefs::kInvalidationServiceUseGCMChannel, true);
   EXPECT_EQ(TiclInvalidationService::GCM_NETWORK_CHANNEL, GetNetworkChannel());
 
-  // If invalidation channel setting is not set or says false, fall back to push
-  // channel.
   prefs->SetBoolean(prefs::kGCMChannelEnabled, true);
-
   prefs->ClearPref(prefs::kInvalidationServiceUseGCMChannel);
-  EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
+  EXPECT_EQ(TiclInvalidationService::GCM_NETWORK_CHANNEL, GetNetworkChannel());
 
-  prefs->SetBoolean(prefs::kInvalidationServiceUseGCMChannel, false);
-  EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
+  prefs->ClearPref(prefs::kGCMChannelEnabled);
+  prefs->SetBoolean(prefs::kInvalidationServiceUseGCMChannel, true);
+  EXPECT_EQ(TiclInvalidationService::GCM_NETWORK_CHANNEL, GetNetworkChannel());
 
-  // If invalidation channel setting says use GCM but GCM is not ALWAYS_ENABLED,
-  // fall back to push channel.
+  // If invalidation channel setting is set to false, fall back to push channel.
+  prefs->SetBoolean(prefs::kGCMChannelEnabled, true);
   prefs->SetBoolean(prefs::kInvalidationServiceUseGCMChannel, false);
-
-  prefs->ClearPref(prefs::kGCMChannelEnabled);
   EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
 
+  // If invalidation channel setting says use GCM but GCM is not enabled, fall
+  // back to push channel.
   prefs->SetBoolean(prefs::kGCMChannelEnabled, false);
-  EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
-
-  // If invalidation channel setting is enabled first and the GCM setting is
-  // enabled after that, switch to GCM channel.
   prefs->SetBoolean(prefs::kInvalidationServiceUseGCMChannel, true);
-  prefs->SetBoolean(prefs::kGCMChannelEnabled, true);
-  EXPECT_EQ(TiclInvalidationService::GCM_NETWORK_CHANNEL, GetNetworkChannel());
+  EXPECT_EQ(TiclInvalidationService::PUSH_CLIENT_CHANNEL, GetNetworkChannel());
 }
 
 }  // namespace invalidation
diff --git a/components/invalidation/ticl_invalidation_service.cc b/components/invalidation/ticl_invalidation_service.cc
index 03dd30e..7fe5aee 100644
--- a/components/invalidation/ticl_invalidation_service.cc
+++ b/components/invalidation/ticl_invalidation_service.cc
@@ -63,7 +63,7 @@ TiclInvalidationService::TiclInvalidationService(
       settings_provider_(settings_provider.Pass()),
       invalidator_registrar_(new syncer::InvalidatorRegistrar()),
       request_access_token_backoff_(&kRequestAccessTokenBackoffPolicy),
-      network_channel_type_(PUSH_CLIENT_CHANNEL),
+      network_channel_type_(GCM_NETWORK_CHANNEL),
       gcm_driver_(gcm_driver),
       request_context_(request_context),
       logger_() {}
diff --git a/sync/internal_api/public/util/experiments.h b/sync/internal_api/public/util/experiments.h
index 9063cbb..b61742d 100644
--- a/sync/internal_api/public/util/experiments.h
+++ b/sync/internal_api/public/util/experiments.h
@@ -29,7 +29,8 @@ struct Experiments {
       : favicon_sync_limit(200),
         gcm_channel_state(UNSET),
         enhanced_bookmarks_enabled(false),
-        gcm_invalidations_enabled(false) {}
+        gcm_invalidations_enabled(true)  // By default GCM channel is enabled.
+  {}
 
   bool Matches(const Experiments& rhs) {
     return (favicon_sync_limit == rhs.favicon_sync_limit &&