[cast_channel] Make CastSocket not inherit from ApiResource

extensions/browser/api/cast_channel/cast_test_util.cc

Index: extensions/browser/api/cast_channel/cast_test_util.cc
diff --git a/extensions/browser/api/cast_channel/cast_test_util.cc b/extensions/browser/api/cast_channel/cast_test_util.cc
index 7a115f2bf6d6edb9bef45858ad4cb2f5bf08da4a..f7246746b236c324eae55b3e312785bbb42c5463 100644
--- a/extensions/browser/api/cast_channel/cast_test_util.cc
+++ b/extensions/browser/api/cast_channel/cast_test_util.cc
@@ -35,11 +35,15 @@ MockCastTransportDelegate::~MockCastTransportDelegate() {
 }
 
 MockCastSocket::MockCastSocket()
-    : CastSocket(kTestExtensionId), mock_transport_(new MockCastTransport) {
-}
+    : mock_transport_(new MockCastTransport),
+      owner_extension_id_(kTestExtensionId) {}
 MockCastSocket::~MockCastSocket() {
 }
 
+const std::string& MockCastSocket::owner_extension_id() const {
+  return owner_extension_id_;
+}
+
 net::IPEndPoint CreateIPEndPointForTest() {
   return net::IPEndPoint(net::IPAddress(192, 168, 1, 1), 8009);
 }