Use backup pollser instead of connectivity watcher
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index b0ac155..d28ef4c 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -299,10 +299,9 @@
                       'src/core/tsi/transport_security_adapter.h',
                       'src/core/tsi/transport_security_interface.h',
                       'src/core/ext/transport/chttp2/server/chttp2_server.h',
-                      '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',
@@ -670,12 +669,11 @@
                       'src/core/tsi/transport_security_adapter.cc',
                       'src/core/ext/transport/chttp2/server/chttp2_server.cc',
                       'src/core/ext/transport/chttp2/client/secure/secure_channel_create.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/channel_connectivity_internal.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',
@@ -806,10 +804,9 @@
                               'src/core/tsi/transport_security_adapter.h',
                               'src/core/tsi/transport_security_interface.h',
                               'src/core/ext/transport/chttp2/server/chttp2_server.h',
-                              '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',