Move channel plugin from grpc_impl to grpc

Reverts: https://github.com/grpc/grpc/pull/18375

BUILD

@@ -2368,7 +2368,6 @@ grpc_cc_library(
     language = "c++",
     public_hdrs = [
         "include/grpcpp/ext/channelz_service_plugin.h",
-        "include/grpcpp/ext/channelz_service_plugin_impl.h",
     ],
     deps = [
         ":grpc++",

CMakeLists.txt

@@ -3636,7 +3636,6 @@ target_link_libraries(grpcpp_channelz
 
 foreach(_hdr
   include/grpcpp/ext/channelz_service_plugin.h
-  include/grpcpp/ext/channelz_service_plugin_impl.h
 )
   string(REPLACE "include/" "" _path ${_hdr})
   get_filename_component(_path ${_path} PATH)

Makefile

@@ -3574,7 +3574,6 @@ LIBGRPCPP_CHANNELZ_SRC = \
 
 PUBLIC_HEADERS_CXX += \
     include/grpcpp/ext/channelz_service_plugin.h \
-    include/grpcpp/ext/channelz_service_plugin_impl.h \
 
 LIBGRPCPP_CHANNELZ_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(LIBGRPCPP_CHANNELZ_SRC))))
 

build_autogenerated.yaml

@@ -2579,7 +2579,6 @@ libs:
   language: c++
   public_headers:
   - include/grpcpp/ext/channelz_service_plugin.h
-  - include/grpcpp/ext/channelz_service_plugin_impl.h
   headers:
   - src/cpp/server/channelz/channelz_service.h
   src:

include/grpcpp/ext/channelz_service_plugin.h

@@ -19,15 +19,20 @@
 #ifndef GRPCPP_EXT_CHANNELZ_SERVICE_PLUGIN_H
 #define GRPCPP_EXT_CHANNELZ_SERVICE_PLUGIN_H
 
-#include <grpcpp/ext/channelz_service_plugin_impl.h>
+#include <grpc/support/port_platform.h>
+
+#include <grpcpp/impl/server_builder_plugin.h>
+#include <grpcpp/impl/server_initializer.h>
+#include <grpcpp/support/config.h>
 
 namespace grpc {
 namespace channelz {
 namespace experimental {
 
-static inline void InitChannelzService() {
-  ::grpc_impl::channelz::experimental::InitChannelzService();
-}
+/// Add channelz server plugin to \a ServerBuilder. This function should
+/// be called at static initialization time. This service is experimental
+/// for now. Track progress in https://github.com/grpc/grpc/issues/15988.
+void InitChannelzService();
 
 }  // namespace experimental
 }  // namespace channelz

include/grpcpp/ext/channelz_service_plugin_impl.h

@@ -1,41 +0,0 @@
-/*
- *
- * Copyright 2018 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#ifndef GRPCPP_EXT_CHANNELZ_SERVICE_PLUGIN_IMPL_H
-#define GRPCPP_EXT_CHANNELZ_SERVICE_PLUGIN_IMPL_H
-
-#include <grpc/support/port_platform.h>
-
-#include <grpcpp/impl/server_builder_plugin.h>
-#include <grpcpp/impl/server_initializer.h>
-#include <grpcpp/support/config.h>
-
-namespace grpc_impl {
-namespace channelz {
-namespace experimental {
-
-/// Add channelz server plugin to \a ServerBuilder. This function should
-/// be called at static initialization time. This service is experimental
-/// for now. Track progress in https://github.com/grpc/grpc/issues/15988.
-void InitChannelzService();
-
-}  // namespace experimental
-}  // namespace channelz
-}  // namespace grpc_impl
-
-#endif  // GRPCPP_EXT_CHANNELZ_SERVICE_PLUGIN_IMPL_H

src/cpp/server/channelz/channelz_service_plugin.cc

@@ -67,13 +67,6 @@ CreateChannelzServicePlugin() {
       new ChannelzServicePlugin());
 }
 
-}  // namespace experimental
-}  // namespace channelz
-}  // namespace grpc
-namespace grpc_impl {
-namespace channelz {
-namespace experimental {
-
 void InitChannelzService() {
   static struct Initializer {
     Initializer() {
@@ -85,4 +78,4 @@ void InitChannelzService() {
 
 }  // namespace experimental
 }  // namespace channelz
-}  // namespace grpc_impl
+}  // namespace grpc