Add publicly visible mock for DataChannelInterface

Bug: webrtc:11642
Change-Id: I20fc57122fc29602028f2cc2fb27a0122117f855
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/191840
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32562}
diff --git a/api/BUILD.gn b/api/BUILD.gn
index cc5975f..fd27681 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -792,6 +792,17 @@
     ]
   }
 
+  rtc_source_set("mock_data_channel") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [ "test/mock_data_channel.h" ]
+
+    deps = [
+      ":libjingle_peerconnection_api",
+      "../test:test_support",
+    ]
+  }
+
   rtc_source_set("mock_fec_controller_override") {
     testonly = true
     sources = [ "test/mock_fec_controller_override.h" ]
@@ -1037,6 +1048,7 @@
       ":fake_frame_decryptor",
       ":fake_frame_encryptor",
       ":mock_audio_mixer",
+      ":mock_data_channel",
       ":mock_frame_decryptor",
       ":mock_frame_encryptor",
       ":mock_peer_connection_factory_interface",
diff --git a/api/test/compile_all_headers.cc b/api/test/compile_all_headers.cc
index 4cece5b..0f50f58 100644
--- a/api/test/compile_all_headers.cc
+++ b/api/test/compile_all_headers.cc
@@ -31,6 +31,7 @@
 #include "api/test/fake_frame_decryptor.h"
 #include "api/test/fake_frame_encryptor.h"
 #include "api/test/mock_audio_mixer.h"
+#include "api/test/mock_data_channel.h"
 #include "api/test/mock_frame_decryptor.h"
 #include "api/test/mock_frame_encryptor.h"
 #include "api/test/mock_peer_connection_factory_interface.h"
diff --git a/api/test/mock_data_channel.h b/api/test/mock_data_channel.h
new file mode 100644
index 0000000..9346ffd
--- /dev/null
+++ b/api/test/mock_data_channel.h
@@ -0,0 +1,60 @@
+/*
+ *  Copyright 2020 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef API_TEST_MOCK_DATA_CHANNEL_H_
+#define API_TEST_MOCK_DATA_CHANNEL_H_
+
+#include <string>
+
+#include "api/data_channel_interface.h"
+#include "test/gmock.h"
+
+namespace webrtc {
+
+class MockDataChannelInterface final
+    : public rtc::RefCountedObject<webrtc::DataChannelInterface> {
+ public:
+  static rtc::scoped_refptr<MockDataChannelInterface> Create() {
+    return new MockDataChannelInterface();
+  }
+
+  MOCK_METHOD(void,
+              RegisterObserver,
+              (DataChannelObserver * observer),
+              (override));
+  MOCK_METHOD(void, UnregisterObserver, (), (override));
+  MOCK_METHOD(std::string, label, (), (const, override));
+  MOCK_METHOD(bool, reliable, (), (const, override));
+  MOCK_METHOD(bool, ordered, (), (const, override));
+  MOCK_METHOD(uint16_t, maxRetransmitTime, (), (const, override));
+  MOCK_METHOD(uint16_t, maxRetransmits, (), (const, override));
+  MOCK_METHOD(absl::optional<int>, maxRetransmitsOpt, (), (const, override));
+  MOCK_METHOD(absl::optional<int>, maxPacketLifeTime, (), (const, override));
+  MOCK_METHOD(std::string, protocol, (), (const, override));
+  MOCK_METHOD(bool, negotiated, (), (const, override));
+  MOCK_METHOD(int, id, (), (const, override));
+  MOCK_METHOD(Priority, priority, (), (const, override));
+  MOCK_METHOD(DataState, state, (), (const, override));
+  MOCK_METHOD(RTCError, error, (), (const, override));
+  MOCK_METHOD(uint32_t, messages_sent, (), (const, override));
+  MOCK_METHOD(uint64_t, bytes_sent, (), (const, override));
+  MOCK_METHOD(uint32_t, messages_received, (), (const, override));
+  MOCK_METHOD(uint64_t, bytes_received, (), (const, override));
+  MOCK_METHOD(uint64_t, buffered_amount, (), (const, override));
+  MOCK_METHOD(void, Close, (), (override));
+  MOCK_METHOD(bool, Send, (const DataBuffer& buffer), (override));
+
+ protected:
+  MockDataChannelInterface() = default;
+};
+
+}  // namespace webrtc
+
+#endif  // API_TEST_MOCK_DATA_CHANNEL_H_
diff --git a/api/test/mock_peer_connection_factory_interface.h b/api/test/mock_peer_connection_factory_interface.h
index 19c3f40..7319ceb 100644
--- a/api/test/mock_peer_connection_factory_interface.h
+++ b/api/test/mock_peer_connection_factory_interface.h
@@ -22,7 +22,7 @@
 class MockPeerConnectionFactoryInterface final
     : public rtc::RefCountedObject<webrtc::PeerConnectionFactoryInterface> {
  public:
-  rtc::scoped_refptr<MockPeerConnectionFactoryInterface> Create() {
+  static rtc::scoped_refptr<MockPeerConnectionFactoryInterface> Create() {
     return new MockPeerConnectionFactoryInterface();
   }