Track when QUIC connections are application limited. Protected by quic_enable_app_limited_check.

net/quic/test_tools/quic_test_utils.h

Index: net/quic/test_tools/quic_test_utils.h
diff --git a/net/quic/test_tools/quic_test_utils.h b/net/quic/test_tools/quic_test_utils.h
index fb5ed36b6a57616b40ea21f11c182ca98ec2d7c8..d1883ae9caf9dc5d03e0d6b9d294e4873480f37a 100644
--- a/net/quic/test_tools/quic_test_utils.h
+++ b/net/quic/test_tools/quic_test_utils.h
@@ -760,6 +760,7 @@ class MockSendAlgorithm : public SendAlgorithmInterface {
   MOCK_CONST_METHOD0(GetCongestionControlType, CongestionControlType());
   MOCK_METHOD2(ResumeConnectionState,
                void(const CachedNetworkParameters&, bool));
+  MOCK_METHOD1(OnApplicationLimited, void(QuicByteCount));
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockSendAlgorithm);
@@ -954,6 +955,7 @@ class MockSentPacketManager : public QuicSentPacketManagerInterface {
   MOCK_CONST_METHOD0(InSlowStart, bool(void));
   MOCK_CONST_METHOD0(GetConsecutiveRtoCount, size_t(void));
   MOCK_CONST_METHOD0(GetConsecutiveTlpCount, size_t(void));
+  MOCK_METHOD0(OnApplicationLimited, void(void));
 };
 
 class MockConnectionCloseDelegate