remove unnecessary comments & using DISABLE_* to disable corresponding UTs

src/butil/time/time.cc

@@ -215,21 +215,6 @@ bool Time::FromStringInternal(const char* time_string,
   // TODO(zhujiashun): after removing nspr, this function
   // is left unimplemented.
   return false;
-  // DCHECK((time_string != NULL) && (parsed_time != NULL));
-
-  // if (time_string[0] == '\0')
-  //   return false;
-
-  // PRTime result_time = 0;
-  // PRStatus result = PR_ParseTimeString(time_string,
-  //                                      is_local ? PR_FALSE : PR_TRUE,
-  //                                      &result_time);
-  // if (PR_SUCCESS != result)
-  //   return false;
-
-  // result_time += kTimeTToMicrosecondsOffset;
-  // *parsed_time = Time(result_time);
-  // return true;
 }
 
 // Local helper class to hold the conversion from Time to TickTime at the