Use backup pollser instead of connectivity watcher
diff --git a/BUILD b/BUILD
index 0e59e78..4c7376c 100644
--- a/BUILD
+++ b/BUILD
@@ -872,12 +872,11 @@
 grpc_cc_library(
     name = "grpc_client_channel",
     srcs = [
-        "src/core/ext/filters/client_channel/channel_connectivity_internal.cc",
+        "src/core/ext/filters/client_channel/backup_poller.cc",
         "src/core/ext/filters/client_channel/channel_connectivity.cc",
         "src/core/ext/filters/client_channel/client_channel.cc",
         "src/core/ext/filters/client_channel/client_channel_factory.cc",
         "src/core/ext/filters/client_channel/client_channel_plugin.cc",
-        "src/core/ext/filters/client_channel/connectivity_watcher.cc",
         "src/core/ext/filters/client_channel/connector.cc",
         "src/core/ext/filters/client_channel/http_connect_handshaker.cc",
         "src/core/ext/filters/client_channel/http_proxy.cc",
@@ -896,10 +895,9 @@
         "src/core/ext/filters/client_channel/uri_parser.cc",
     ],
     hdrs = [
-        "src/core/ext/filters/client_channel/channel_connectivity_internal.h",
+        "src/core/ext/filters/client_channel/backup_poller.h",
         "src/core/ext/filters/client_channel/client_channel.h",
         "src/core/ext/filters/client_channel/client_channel_factory.h",
-        "src/core/ext/filters/client_channel/connectivity_watcher.h",
         "src/core/ext/filters/client_channel/connector.h",
         "src/core/ext/filters/client_channel/http_connect_handshaker.h",
         "src/core/ext/filters/client_channel/http_proxy.h",