Invalidations cleanup: Delete NetworkChannel interface

It had a single implementation, FCMSyncNetworkChannel, and nothing
actually referred to the interface.

Bug: 1029481
Change-Id: I4791dd4a4760687f29499faee7986d1dfefb5745
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2062422
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Auto-Submit: Marc Treib <treib@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743029}

components/invalidation/impl/BUILD.gn

@@ -40,7 +40,6 @@ static_library("impl") {
     "invalidator_registrar_with_memory.h",
     "mock_ack_handler.cc",
     "mock_ack_handler.h",
-    "network_channel.h",
     "per_user_topic_subscription_manager.cc",
     "per_user_topic_subscription_manager.h",
     "per_user_topic_subscription_request.cc",

components/invalidation/impl/fcm_invalidation_listener.cc

@@ -7,7 +7,6 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
-#include "components/invalidation/impl/network_channel.h"
 #include "components/invalidation/public/invalidation_util.h"
 #include "components/invalidation/public/object_id_invalidation_map.h"
 #include "components/invalidation/public/topic_invalidation_map.h"

components/invalidation/impl/fcm_network_handler_unittests.cc

@@ -22,7 +22,6 @@
 #include "components/gcm_driver/instance_id/instance_id.h"
 #include "components/gcm_driver/instance_id/instance_id_driver.h"
 #include "components/invalidation/impl/invalidation_switches.h"
-#include "components/invalidation/impl/network_channel.h"
 #include "components/invalidation/impl/status.h"
 #include "google_apis/gcm/engine/account_mapping.h"
 #include "services/network/public/cpp/weak_wrapper_shared_url_loader_factory.h"
@@ -167,7 +166,7 @@ class MockInstanceIDDriver : public InstanceIDDriver {
 
 class MockOnTokenCallback {
  public:
-  TokenCallback Get() {
+  FCMSyncNetworkChannel::TokenCallback Get() {
     return base::BindRepeating(&MockOnTokenCallback::Run,
                                base::Unretained(this));
   }
@@ -177,7 +176,7 @@ class MockOnTokenCallback {
 
 class MockOnMessageCallback {
  public:
-  MessageCallback Get() {
+  FCMSyncNetworkChannel::MessageCallback Get() {
     return base::BindRepeating(&MockOnMessageCallback::Run,
                                base::Unretained(this));
   }
@@ -214,7 +213,7 @@ class FCMNetworkHandlerTest : public testing::Test {
   }
 
   std::unique_ptr<FCMNetworkHandler> MakeHandlerReadyForMessage(
-      MessageCallback mock_on_message_callback) {
+      FCMSyncNetworkChannel::MessageCallback mock_on_message_callback) {
     std::unique_ptr<FCMNetworkHandler> handler = MakeHandler();
     handler->SetMessageReceiver(mock_on_message_callback);
     EXPECT_CALL(*mock_instance_id(), GetToken(_, _, _, _, _, _))

components/invalidation/impl/fcm_sync_network_channel.h

@@ -5,11 +5,12 @@
 #ifndef COMPONENTS_INVALIDATION_IMPL_FCM_SYNC_NETWORK_CHANNEL_H_
 #define COMPONENTS_INVALIDATION_IMPL_FCM_SYNC_NETWORK_CHANNEL_H_
 
+#include <string>
+
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "base/values.h"
 #include "components/invalidation/impl/channels_states.h"
-#include "components/invalidation/impl/network_channel.h"
 
 namespace syncer {
 
@@ -17,7 +18,7 @@ namespace syncer {
 // client:
 //  - registering message callbacks
 //  - notifying on network problems
-class FCMSyncNetworkChannel : public NetworkChannel {
+class FCMSyncNetworkChannel {
  public:
   class Observer {
    public:
@@ -25,14 +26,36 @@ class FCMSyncNetworkChannel : public NetworkChannel {
         FcmChannelState invalidator_state) = 0;
   };
 
+  // See SetMessageReceiver below.
+  //   payload - additional info specific to the invalidation
+  //   private_topic - the internal (to FCM) representation for the public topic
+  //   public_topic - the topic which was invalidated, e.g. in case of Chrome
+  //                  Sync it'll be BOOKMARK or PASSWORD
+  //   version - version number of the invalidation
+  using MessageCallback =
+      base::RepeatingCallback<void(const std::string& payload,
+                                   const std::string& private_topic,
+                                   const std::string& public_topic,
+                                   int64_t version)>;
+
+  using TokenCallback = base::RepeatingCallback<void(const std::string& token)>;
+
   FCMSyncNetworkChannel();
-  ~FCMSyncNetworkChannel() override;
+  virtual ~FCMSyncNetworkChannel();
 
   virtual void StartListening() = 0;
   virtual void StopListening() = 0;
 
-  void SetMessageReceiver(MessageCallback incoming_receiver) override;
-  void SetTokenReceiver(TokenCallback token_receiver) override;
+  // Sets the receiver to which messages from the data center will be delivered.
+  // The callback will be invoked whenever an invalidation message is received
+  // from FCM. It is *not* guaranteed to be invoked exactly once or in-order
+  // (with respect to the invalidation's version number).
+  void SetMessageReceiver(MessageCallback incoming_receiver);
+
+  // Sets the receiver to which FCM registration token will be delivered.
+  // The callback will be invoked whenever a new InstanceID token becomes
+  // available.
+  void SetTokenReceiver(TokenCallback token_receiver);
 
   // Classes interested in network channel state changes should implement
   // FCMSyncNetworkChannel::Observer and register here.

components/invalidation/impl/network_channel.h

-// Copyright 2018 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef COMPONENTS_INVALIDATION_IMPL_NETWORK_CHANNEL_H_
-#define COMPONENTS_INVALIDATION_IMPL_NETWORK_CHANNEL_H_
-
-#include "base/callback.h"
-
-namespace syncer {
-
-// See SetMessageReceiver below.
-//   payload - additional info specific to the invalidation
-//   private_topic - the internal (to FCM) representation for the public topic
-//   public_topic - the topic which was invalidated, e.g. in case of Chrome
-//                  Sync it'll be BOOKMARK or PASSWORD
-//   version - version number of the invalidation
-using MessageCallback =
-    base::RepeatingCallback<void(const std::string& payload,
-                                 const std::string& private_topic,
-                                 const std::string& public_topic,
-                                 int64_t version)>;
-
-using TokenCallback = base::RepeatingCallback<void(const std::string& token)>;
-
-// Interface specifying the functionality of the network, required by
-// invalidation client.
-// TODO(crbug.com/1029481): Get rid of this interface; it has a single
-// implementation and nothing refers to it directly.
-class NetworkChannel {
- public:
-  virtual ~NetworkChannel() {}
-
-  // Sets the receiver to which messages from the data center will be delivered.
-  // The callback will be invoked whenever an invalidation message is received
-  // from FCM. It is *not* guaranteed to be invoked exactly once or in-order
-  // (with respect to the invalidation's version number).
-  virtual void SetMessageReceiver(MessageCallback incoming_receiver) = 0;
-
-  // Sets the receiver to which FCM registration token will be delivered.
-  // The callback will be invoked whenever a new InstanceID token becomes
-  // available.
-  virtual void SetTokenReceiver(TokenCallback incoming_receiver) = 0;
-};
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_INVALIDATION_IMPL_NETWORK_CHANNEL_H_