Delete system_wrappers logging facility.

webrtc/system_wrappers/BUILD.gn

Index: webrtc/system_wrappers/BUILD.gn
diff --git a/webrtc/system_wrappers/BUILD.gn b/webrtc/system_wrappers/BUILD.gn
index 708fd318f0f6272cce9da2672a91b29500297c1e..bbb1b12ba37b23d8f4475910557f0445459c1f7f 100644
--- a/webrtc/system_wrappers/BUILD.gn
+++ b/webrtc/system_wrappers/BUILD.gn
@@ -24,7 +24,6 @@ rtc_static_library("system_wrappers") {
     "include/field_trial.h",
     "include/file_wrapper.h",
     "include/fix_interlocked_exchange_pointer_win.h",
-    "include/logging.h",
     "include/metrics.h",
     "include/ntp_time.h",
     "include/rtp_to_ntp_estimator.h",
@@ -45,7 +44,6 @@ rtc_static_library("system_wrappers") {
     "source/event_timer_win.cc",
     "source/event_timer_win.h",
     "source/file_impl.cc",
-    "source/logging.cc",
     "source/rtp_to_ntp_estimator.cc",
     "source/rw_lock.cc",
     "source/rw_lock_posix.cc",
@@ -167,7 +165,6 @@ if (rtc_include_tests) {
       "source/aligned_malloc_unittest.cc",
       "source/clock_unittest.cc",
       "source/event_timer_posix_unittest.cc",
-      "source/logging_unittest.cc",
       "source/metrics_default_unittest.cc",
       "source/metrics_unittest.cc",
       "source/ntp_time_unittest.cc",