[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..d5406b0f9fbc39a9ea860fb9aa7021398563e8db 100644
--- a/extensions/browser/api/cast_channel/cast_test_util.cc
+++ b/extensions/browser/api/cast_channel/cast_test_util.cc
@@ -34,9 +34,7 @@ MockCastTransportDelegate::MockCastTransportDelegate() {
 MockCastTransportDelegate::~MockCastTransportDelegate() {
 }
 
-MockCastSocket::MockCastSocket()
-    : CastSocket(kTestExtensionId), mock_transport_(new MockCastTransport) {
-}
+MockCastSocket::MockCastSocket() : mock_transport_(new MockCastTransport()) {}
 MockCastSocket::~MockCastSocket() {
 }