Add notice when parallel recompilation is disabled by tracing.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/22164002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16043 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/v8.cc

@@ -272,9 +272,10 @@ void V8::InitializeOncePerProcessImpl() {
     FLAG_max_new_space_size = (1 << (kPageSizeBits - 10)) * 2;
   }
 
-  if (FLAG_trace_hydrogen || FLAG_trace_hydrogen_stubs) {
-    // Tracing hydrogen do not work with parallel recompilation.
+  if (FLAG_parallel_recompilation &&
+      (FLAG_trace_hydrogen || FLAG_trace_hydrogen_stubs)) {
     FLAG_parallel_recompilation = false;
+    PrintF("Parallel recompilation has been disabled for tracing.\n");
   }
 
   if (FLAG_sweeper_threads <= 0) {