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

webrtc/system_wrappers/source/logging.cc

Index: webrtc/system_wrappers/source/logging.cc
diff --git a/webrtc/system_wrappers/source/logging.cc b/webrtc/system_wrappers/source/logging.cc
index da1c1a57d8a75f39362bdeda88b45d90c6025135..45a0985454486e1da9389084453de4b6619fa15f 100644
--- a/webrtc/system_wrappers/source/logging.cc
+++ b/webrtc/system_wrappers/source/logging.cc
@@ -32,7 +32,8 @@ TraceLevel WebRtcSeverity(LoggingSeverity sev) {
   }
 }
 
-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)
@@ -45,7 +46,7 @@ const char* DescribeFile(const char* file) {
 
 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) {