Disable base/logging.h stderr logs by default for webrtc/ tests.

webrtc/system_wrappers/source/logging.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 14 matching lines @@
     // TODO(ajm): SENSITIVE doesn't have a corresponding webrtc level.
     case LS_SENSITIVE:  return kTraceInfo;
     case LS_VERBOSE:    return kTraceInfo;
     case LS_INFO:       return kTraceTerseInfo;
     case LS_WARNING:    return kTraceWarning;
     case LS_ERROR:      return kTraceError;
     default:            return kTraceNone;
   }
 }
 
-const char* DescribeFile(const char* file) {
+// Return the filename portion of the string (that following the last slash).
+const char* FilenameFromPath(const char* file) {
   const char* end1 = ::strrchr(file, '/');
   const char* end2 = ::strrchr(file, '\\');
   if (!end1 && !end2)
     return file;
   else
     return (end1 > end2) ? end1 + 1 : end2 + 1;
 }
 
 }  // namespace
 
 LogMessage::LogMessage(const char* file, int line, LoggingSeverity sev)
     : severity_(sev) {
-  print_stream_ << "(" << DescribeFile(file) << ":" << line << "): ";
+  print_stream_ << "(" << FilenameFromPath(file) << ":" << line << "): ";
 }
 
 bool LogMessage::Loggable(LoggingSeverity sev) {
   // |level_filter| is a bitmask, unlike libjingle's minimum severity value.
   return WebRtcSeverity(sev) & Trace::level_filter() ? true : false;
 }
 
 LogMessage::~LogMessage() {
   const std::string& str = print_stream_.str();
   Trace::Add(WebRtcSeverity(severity_), kTraceUndefined, 0, "%s", str.c_str());
 }
 
 }  // namespace webrtc