Add quic_logging

net/quic/test_tools/simulator/README.md

 # QUIC network simulator
 
 This directory contains a discrete event network simulator which QUIC code uses
 for testing congestion control and other transmission control code that requires
 a network simulation for tests on QuicConnection level of abstraction.
 
 ## Actors
 
 The core of the simulator is the Simulator class, which maintains a virtual
 clock and an event queue. Any object in a simulation that needs to schedule
@@ skipping 12 matching lines @@
 
 ```c++
 class LogClock : public Actor {
  public:
   LogClock(Simulator* simulator, std::string name) : Actor(simulator, name) {
     Schedule(clock_->Now());
   }
   ~LogClock() override {}
 
   void Act() override {
-    VLOG(1) << "The current time is " << clock_->Now().ToDebuggingValue();
+    QUIC_LOG(INFO) << "The current time is " << clock_->Now().ToDebuggingValue();
     Schedule(clock_->Now() + QuicTime::Delta::FromMilliseconds(100));
   }
 };
 ```
 
 A QuicAlarm object can be used to schedule events in the simulation using
 `Simulator::GetAlarmFactory()`.
 
 ## Ports
 
@@ skipping 45 matching lines @@
 Besides `SymmetricLink`, the simulator provides the following objects:
 
 *   `Queue` allows to convert a constrained port into an unconstrained one by
     buffering packets upon arrival. The queue has a finite size, and once the
     queue is full, the packets are silently dropped.
 *   `Switch` simulates a multi-port learning switch with a fixed queue for each
     output port.
 *   `QuicEndpoint` allows QuicConnection to be run over the simulated network.
 *   `QuicEndpointMultiplexer` allows multiple connections to share the same
     network endpoint.