Split out QuicAlarm creation from QuicConnectionHelper to new QuicAlarmFactory.

net/quic/test_tools/mock_quic_dispatcher.h

Index: net/quic/test_tools/mock_quic_dispatcher.h
diff --git a/net/quic/test_tools/mock_quic_dispatcher.h b/net/quic/test_tools/mock_quic_dispatcher.h
index 05c9c9baa550187df32e80aa69f2d3a2c9bd2b6e..d359c33b750723bd4f80500d9da36ebc87a5b38d 100644
--- a/net/quic/test_tools/mock_quic_dispatcher.h
+++ b/net/quic/test_tools/mock_quic_dispatcher.h
@@ -20,7 +20,8 @@ class MockQuicDispatcher : public QuicDispatcher {
  public:
   MockQuicDispatcher(const QuicConfig& config,
                      const QuicCryptoServerConfig* crypto_config,
-                     QuicConnectionHelperInterface* helper);
+                     QuicConnectionHelperInterface* helper,
+                     QuicAlarmFactory* alarm_factory);
 
   ~MockQuicDispatcher() override;