Copy event label.

runtime/vm/timeline.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <cstdlib>
 
 #include "vm/atomic.h"
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/lockers.h"
@@ skipping 281 matching lines @@
 TimelineEvent::~TimelineEvent() {
   Reset();
 }
 
 
 void TimelineEvent::Reset() {
   state_ = 0;
   thread_ = OSThread::kInvalidThreadId;
   isolate_id_ = ILLEGAL_PORT;
   category_ = "";
-  label_ = NULL;
+  if (label_ != NULL) {
+    free(label_);
+    label_ = NULL;
+  }
   FreeArguments();
   set_pre_serialized_json(false);
   set_event_type(kNone);
 }
 
 
 void TimelineEvent::AsyncBegin(const char* label,
                                int64_t async_id,
                                int64_t micros) {
   Init(kAsyncBegin, label);
@@ skipping 178 matching lines @@
   timestamp1_ = 0;
   OSThread* os_thread = OSThread::Current();
   ASSERT(os_thread != NULL);
   thread_ = os_thread->trace_id();
   Isolate* isolate = Isolate::Current();
   if (isolate != NULL) {
     isolate_id_ = isolate->main_port();
   } else {
     isolate_id_ = ILLEGAL_PORT;
   }
-  label_ = label;
+  label_ = strdup(label);

[Cutch, 2016/04/14 13:24:29]

The timeline was designed to require const char* for the label to avoid doing
this string copy. 

Flutter should give us const char* for the labels, or, change this CL to make
copying of the label optional and only use it for events delivered via the API.

   FreeArguments();
   set_pre_serialized_json(false);
   set_event_type(event_type);
 }
 
 
 bool TimelineEvent::Within(int64_t time_origin_micros,
                            int64_t time_extent_micros) {
   if ((time_origin_micros == -1) ||
       (time_extent_micros == -1)) {
@@ skipping 1043 matching lines @@
 TimelineEventBlock* TimelineEventBlockIterator::Next() {
   ASSERT(current_ != NULL);
   TimelineEventBlock* r = current_;
   current_ = current_->next();
   return r;
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart