Generate globally (cross-process) unique IDs for memory tracing dumps

base/trace_event/trace_event_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifndef BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_
 #define BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_
 
 #include <stack>
 #include <string>
@@ skipping 584 matching lines @@
   typedef base::Callback<void()> WatchEventCallback;
   void SetWatchEvent(const std::string& category_name,
                      const std::string& event_name,
                      const WatchEventCallback& callback);
   // Cancel the watch event. If tracing is enabled, this may race with the
   // watch event notification firing.
   void CancelWatchEvent();
 
   int process_id() const { return process_id_; }
 
+  uint64 HashEventId(uint64 id);

[Primiano Tucci (use gerrit), 2015/04/13 22:13:58]

I think this should be called MangleEventId, but I defer to Dan here.

[dsinclair, 2015/04/14 13:42:46]

+1 we use mangle in other places in the trace event framework.

+
   // Exposed for unittesting:
 
   void WaitSamplingEventForTesting();
 
   // Allows deleting our singleton instance.
   static void DeleteForTesting();
 
   // Allow tests to inspect TraceEvents.
   TraceEvent* GetEventByHandle(TraceEventHandle handle);
 
@@ skipping 189 matching lines @@
   scoped_refptr<MessageLoopProxy> flush_message_loop_proxy_;
   subtle::AtomicWord generation_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceLog);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_