Only call to LogSymbol when needed.

src/preparser.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1214 matching lines @@
     CheckOctalLiteral(start_position, end_position, CHECK_OK);
     return Expression::StrictFunction();
   }
 
   return Expression::Default();
 }
 
 
 void PreParser::ParseLazyFunctionLiteralBody(bool* ok) {
   int body_start = position();
-  log_->PauseRecording();
+  bool is_logging = log_->ShouldLogSymbols();
+  if (is_logging) log_->PauseRecording();
   ParseSourceElements(Token::RBRACE, ok);
-  log_->ResumeRecording();
+  if (is_logging) log_->ResumeRecording();
   if (!*ok) return;
 
   // Position right after terminal '}'.
   ASSERT_EQ(Token::RBRACE, scanner()->peek());
   int body_end = scanner()->peek_location().end_pos;
   log_->LogFunction(body_start, body_end,
                     function_state_->materialized_literal_count(),
                     function_state_->expected_property_count(),
                     strict_mode());
 }
@@ skipping 11 matching lines @@
   ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   ParseArguments(ok);
 
   return Expression::Default();
 }
 
 #undef CHECK_OK
 
 
 void PreParser::LogSymbol() {
-  scanner()->LogSymbol(log_, position());
+  if (log_->ShouldLogSymbols()) {
+    scanner()->LogSymbol(log_, position());
+  }
 }
 
 
 } }  // v8::internal