Remove ChannelInterface and replace it with Channel
diff --git a/test/cpp/interop/client.cc b/test/cpp/interop/client.cc
index 48143b2..d9e4f1b 100644
--- a/test/cpp/interop/client.cc
+++ b/test/cpp/interop/client.cc
@@ -38,7 +38,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 #include <gflags/gflags.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/status.h>
 #include <grpc++/stream.h>
diff --git a/test/cpp/interop/client_helper.cc b/test/cpp/interop/client_helper.cc
index b8a222c..91c8dbc 100644
--- a/test/cpp/interop/client_helper.cc
+++ b/test/cpp/interop/client_helper.cc
@@ -44,7 +44,7 @@
 #include <grpc/support/log.h>
 #include <gflags/gflags.h>
 #include <grpc++/channel_arguments.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/create_channel.h>
 #include <grpc++/credentials.h>
 #include <grpc++/stream.h>
@@ -103,7 +103,7 @@
   return access_token;
 }
 
-std::shared_ptr<ChannelInterface> CreateChannelForTestCase(
+std::shared_ptr<Channel> CreateChannelForTestCase(
     const grpc::string& test_case) {
   GPR_ASSERT(FLAGS_server_port);
   const int host_port_buf_size = 1024;
diff --git a/test/cpp/interop/client_helper.h b/test/cpp/interop/client_helper.h
index 000374a..3b46d87 100644
--- a/test/cpp/interop/client_helper.h
+++ b/test/cpp/interop/client_helper.h
@@ -37,7 +37,7 @@
 #include <memory>
 
 #include <grpc++/config.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 
 namespace grpc {
 namespace testing {
@@ -46,7 +46,7 @@
 
 grpc::string GetOauth2AccessToken();
 
-std::shared_ptr<ChannelInterface> CreateChannelForTestCase(
+std::shared_ptr<Channel> CreateChannelForTestCase(
     const grpc::string& test_case);
 
 class InteropClientContextInspector {
diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index 5ed14d5..c73505c 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -42,7 +42,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/credentials.h>
 #include <grpc++/status.h>
@@ -84,7 +84,7 @@
 }
 }  // namespace
 
-InteropClient::InteropClient(std::shared_ptr<ChannelInterface> channel)
+InteropClient::InteropClient(std::shared_ptr<Channel> channel)
     : channel_(channel) {}
 
 void InteropClient::AssertOkOrPrintErrorStatus(const Status& s) {
diff --git a/test/cpp/interop/interop_client.h b/test/cpp/interop/interop_client.h
index d6fb9bf..354c2c6 100644
--- a/test/cpp/interop/interop_client.h
+++ b/test/cpp/interop/interop_client.h
@@ -36,7 +36,7 @@
 #include <memory>
 
 #include <grpc/grpc.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/status.h>
 #include "test/proto/messages.grpc.pb.h"
 
@@ -45,10 +45,10 @@
 
 class InteropClient {
  public:
-  explicit InteropClient(std::shared_ptr<ChannelInterface> channel);
+  explicit InteropClient(std::shared_ptr<Channel> channel);
   ~InteropClient() {}
 
-  void Reset(std::shared_ptr<ChannelInterface> channel) { channel_ = channel; }
+  void Reset(std::shared_ptr<Channel> channel) { channel_ = channel; }
 
   void DoEmpty();
   void DoLargeUnary();
@@ -82,7 +82,7 @@
   void PerformLargeUnary(SimpleRequest* request, SimpleResponse* response);
   void AssertOkOrPrintErrorStatus(const Status& s);
 
-  std::shared_ptr<ChannelInterface> channel_;
+  std::shared_ptr<Channel> channel_;
 };
 
 }  // namespace testing
diff --git a/test/cpp/interop/reconnect_interop_client.cc b/test/cpp/interop/reconnect_interop_client.cc
index 65f0980..675c6ff 100644
--- a/test/cpp/interop/reconnect_interop_client.cc
+++ b/test/cpp/interop/reconnect_interop_client.cc
@@ -37,7 +37,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
 #include <gflags/gflags.h>
-#include <grpc++/channel_interface.h>
+#include <grpc++/channel.h>
 #include <grpc++/client_context.h>
 #include <grpc++/status.h>
 #include "test/cpp/util/create_test_channel.h"
@@ -50,7 +50,7 @@
 DEFINE_int32(server_retry_port, 0, "Server port for testing reconnection.");
 DEFINE_string(server_host, "127.0.0.1", "Server host to connect to");
 
-using grpc::ChannelInterface;
+using grpc::Channel;
 using grpc::ClientContext;
 using grpc::CreateTestChannel;
 using grpc::Status;
@@ -78,7 +78,7 @@
   gpr_log(GPR_INFO, "Starting connections with retries.");
   server_address.str("");
   server_address << FLAGS_server_host << ':' << FLAGS_server_retry_port;
-  std::shared_ptr<ChannelInterface> retry_channel =
+  std::shared_ptr<Channel> retry_channel =
       CreateTestChannel(server_address.str(), true);
   // About 13 retries.
   const int kDeadlineSeconds = 540;