Add media router common classes and unittests.

chrome/browser/media/router/media_sink_unittest.cc

+// Copyright 2015 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 "chrome/browser/media/router/media_sink.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace media_router {
+
+class MediaSinkTest : public ::testing::Test {
+ protected:
+  MediaSinkTest() {}
+  ~MediaSinkTest() override {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaSinkTest);
+};
+
+TEST_F(MediaSinkTest, Equals) {

[xhwang, 2015/03/05 22:28:50]

You probably don't need MediaSinkTest at all. Just use TEST here.

[Kevin M, 2015/03/06 23:12:45]

Done.

+  MediaSink sink1("sinkId", "Sink");
+
+  // Same as sink1.
+  MediaSink sink2("sinkId", "Sink");
+  EXPECT_EQ(sink1, sink2);
+
+  // Sink name is different from sink1's.
+  MediaSink sink3("sinkId", "Other Sink");
+  EXPECT_EQ(sink1, sink3);
+
+  // Sink ID is diffrent from sink1's.
+  MediaSink sink4("otherSinkId", "Sink");
+  EXPECT_NE(sink1, sink4);
+}
+
+}  // namespace media_router