Escape name and category of trace events.

base/trace_event/trace_event_impl.cc

Index: base/trace_event/trace_event_impl.cc
diff --git a/base/trace_event/trace_event_impl.cc b/base/trace_event/trace_event_impl.cc
index 4ab0d358f9d202dd31ba6418b098da6751348e05..3ed0f7dedb60e574587bd8768431775779626cb0 100644
--- a/base/trace_event/trace_event_impl.cc
+++ b/base/trace_event/trace_event_impl.cc
@@ -293,10 +293,12 @@ void TraceEvent::AppendAsJSON(
   // Category group checked at category creation time.
   DCHECK(!strchr(name_, '"'));
   StringAppendF(out, "{\"pid\":%i,\"tid\":%i,\"ts\":%" PRId64
-                     ","
-                     "\"ph\":\"%c\",\"cat\":\"%s\",\"name\":\"%s\",\"args\":",
-                process_id, thread_id, time_int64, phase_, category_group_name,
-                name_);
+                     ",\"ph\":\"%c\",\"cat\":",
+                process_id, thread_id, time_int64, phase_);
+  EscapeJSONString(category_group_name, true, out);

[Primiano Tucci (use gerrit), 2016/04/07 13:30:08]

In which case does a category name contain quotes?
This is just in case right?

[Mario Pistrich, 2016/04/07 13:50:58]

Yeah, I've added it just to be sure - should I remove it?

[Primiano Tucci (use gerrit), 2016/04/07 16:17:56]

I am pretty sure that if somebody adds quotes to the category lot of other
things will break, so I'd probably avoid the perf hit of escaping here.

[Mario Pistrich, 2016/04/07 18:59:52]

Okay, sounds reasonable, I removed escaping the trace event's category.

+  *out += ",\"name\":";
+  EscapeJSONString(name_, true, out);
+  *out += ",\"args\":";
 
   // Output argument names and values, stop at first NULL argument name.
   // TODO(oysteine): The dual predicates here is a bit ugly; if the filtering