Add unit tests for webrtc_media_stream_adapter.cc

content/renderer/media/webrtc/media_stream_video_webrtc_sink_unittest.cc

+// Copyright 2016 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.
+
+#include "content/renderer/media/webrtc/media_stream_video_webrtc_sink.h"
+
+#include "content/child/child_process.h"
+#include "content/renderer/media/mock_constraint_factory.h"
+#include "content/renderer/media/mock_media_stream_registry.h"
+#include "content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+namespace {
+
+class MediaStreamVideoWebRtcSinkTest : public ::testing::Test {
+ public:
+  MediaStreamVideoWebRtcSinkTest() {}
+
+  void SetVideoTrack(blink::WebMediaConstraints constraints) {
+    registry_.Init("stream URL");
+    registry_.AddVideoTrack("test video track", constraints);
+    blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
+    registry_.test_stream().videoTracks(video_tracks);
+    track_ = video_tracks[0];
+    // TODO(hta): Verify that track_ is valid. When constraints produce
+    // no valid format, using the track will cause a crash.
+  }
+
+ protected:
+  blink::WebMediaStreamTrack track_;
+  MockPeerConnectionDependencyFactory dependency_factory_;
+
+ private:
+  MockMediaStreamRegistry registry_;
+  // A ChildProcess and a MessageLoopForUI are both needed to fool the Tracks
+  // and Sources in |registry_| into believing they are on the right threads.
+  base::MessageLoopForUI message_loop_;
+  const ChildProcess child_process_;
+};
+
+TEST_F(MediaStreamVideoWebRtcSinkTest, ObjectConstructor) {

[pbos, 2016/10/10 15:43:32]

Can you put something descriptive of the test, such as
DoesNotSetDenoisingByDefault instead of ObjectConstruction?

Feel free to think of a better name though.

+  blink::WebMediaConstraints constraints;
+  constraints.initialize();
+  SetVideoTrack(constraints);
+  MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
+  EXPECT_TRUE(my_sink.webrtc_video_track());
+  EXPECT_FALSE(my_sink.SourceNeedsDenoisingTestHelper());
+}
+
+TEST_F(MediaStreamVideoWebRtcSinkTest, NoiseReductionConstraintPassThrough) {

[pbos, 2016/10/10 15:43:32]

Pref naming this test PassesThroughNoiseReductionConstraint

+  MockConstraintFactory factory;
+  factory.basic().googNoiseReduction.setExact(true);
+  SetVideoTrack(factory.CreateWebMediaConstraints());
+  MediaStreamVideoWebRtcSink my_sink(track_, &dependency_factory_);
+  EXPECT_TRUE(my_sink.SourceNeedsDenoisingTestHelper());
+  EXPECT_TRUE(*(my_sink.SourceNeedsDenoisingTestHelper()));
+}
+
+}  // namespace
+}  // namespace content