[tracing] Ignore tracing allocations in heap profiler

base/trace_event/trace_log.cc

Index: base/trace_event/trace_log.cc
diff --git a/base/trace_event/trace_log.cc b/base/trace_event/trace_log.cc
index a0b12fbc5426fc1f357b4be8eb219a690ca2c647..72901926cb1a535fc53b32e2135b64b616668aad 100644
--- a/base/trace_event/trace_log.cc
+++ b/base/trace_event/trace_log.cc
@@ -31,6 +31,7 @@
 #include "base/threading/worker_pool.h"
 #include "base/time/time.h"
 #include "base/trace_event/heap_profiler_allocation_context_tracker.h"
+#include "base/trace_event/heap_profiler_scoped_ignore.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/process_memory_dump.h"
@@ -391,6 +392,7 @@ void TraceLog::InitializeThreadLocalEventBufferIfSupported() {
   // trace events will be added into the main buffer directly.
   if (thread_blocks_message_loop_.Get() || !MessageLoop::current())
     return;
+  HEAP_PROFILER_SCOPED_IGNORE;
   auto thread_local_event_buffer = thread_local_event_buffer_.Get();
   if (thread_local_event_buffer &&
       !CheckGeneration(thread_local_event_buffer->generation())) {
@@ -907,6 +909,7 @@ void TraceLog::ConvertTraceEventsToTraceFormat(
   if (flush_output_callback.is_null())
     return;
 
+  HEAP_PROFILER_SCOPED_IGNORE;

[Primiano Tucci (use gerrit), 2016/04/21 19:47:32]

out of curiosity, why this is needed here? This should happen only after the end
of the trace, when you will no longer emit any memory dump, right?

[ssid, 2016/04/22 04:57:12]

Hm, I added this because if there are multiple tracing sessions then this usage
might show up. Or it might not because the memory will get freed. I just added
to be safe and not include it any time.

   // The callback need to be called at least once even if there is no events
   // to let the caller know the completion of flush.
   scoped_refptr<RefCountedString> json_events_str_ptr = new RefCountedString();
@@ -1341,6 +1344,7 @@ void TraceLog::AddMetadataEvent(
     const unsigned long long* arg_values,
     std::unique_ptr<ConvertableToTraceFormat>* convertable_values,
     unsigned int flags) {
+  HEAP_PROFILER_SCOPED_IGNORE;
   std::unique_ptr<TraceEvent> trace_event(new TraceEvent);
   int thread_id = static_cast<int>(base::PlatformThread::CurrentId());
   ThreadTicks thread_now = ThreadNow();
@@ -1361,6 +1365,7 @@ void TraceLog::AddMetadataEvent(
 std::string TraceLog::EventToConsoleMessage(unsigned char phase,
                                             const TimeTicks& timestamp,
                                             TraceEvent* trace_event) {
+  HEAP_PROFILER_SCOPED_IGNORE;
   AutoLock thread_info_lock(thread_info_lock_);
 
   // The caller should translate TRACE_EVENT_PHASE_COMPLETE to
@@ -1664,6 +1669,7 @@ void TraceLog::SetCurrentThreadBlocksMessageLoop() {
 }
 
 TraceBuffer* TraceLog::CreateTraceBuffer() {
+  HEAP_PROFILER_SCOPED_IGNORE;
   InternalTraceOptions options = trace_options();
   if (options & kInternalRecordContinuously)
     return TraceBuffer::CreateTraceBufferRingBuffer(