Configure QuicFlagsImpl to correctly enable support for --v=1.

Change-Id: Iae28c97538f406f27d44181ba280d995e8d276c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1615833
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Nick Harper <nharper@chromium.org>
Auto-Submit: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Nick Harper <nharper@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660611}

net/quic/platform/impl/quic_flags_impl.cc

@@ -201,6 +201,11 @@ std::vector<std::string> QuicParseCommandLineFlagsImpl(
   if (result.exit_status.has_value()) {
     exit(*result.exit_status);
   }
+
+  logging::LoggingSettings settings;
+  settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
+  CHECK(logging::InitLogging(settings));
+
   return result.non_flag_args;
 }