AI 143562: Usability fixes for runtest.py

BUG=1743678

Automated import of CL 143562

testrunner/logger.py

@@ -25,6 +25,7 @@ import datetime
 
 _LOG_FILE = None
 _verbose = False
+_log_time = True
 
 def Init(log_file_path):
   """Set the path to the log file"""
@@ -57,8 +58,13 @@ def _WriteLog(msg):
 
 def _PrependTimeStamp(log_string):
   """Returns the log_string prepended with current timestamp """
-  return "# %s: %s" % (datetime.datetime.now().strftime("%m/%d/%y %H:%M:%S"),
-      log_string)
+  global _log_time
+  if _log_time:
+    return "# %s: %s" % (datetime.datetime.now().strftime("%m/%d/%y %H:%M:%S"),
+        log_string)
+  else:
+    # timestamp logging disabled
+    return log_string  
 
 def SilentLog(new_str):
   """Silently log new_str. Unless verbose mode is enabled, will log new_str
@@ -77,7 +83,12 @@ def SetVerbose(new_verbose=True):
   """ Enable or disable verbose logging"""
   global _verbose
   _verbose = new_verbose
-
+  
+def SetTimestampLogging(new_timestamp=True):
+  """ Enable or disable outputting a timestamp with each log entry"""
+  global _log_time
+  _log_time = new_timestamp
+    
 def main():
   pass