[tracing] Ignore tracing allocations in heap profiler

base/trace_event/heap_profiler.cc

+// Copyright 2015 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.
+
+#include "base/trace_event/heap_profiler.h"
+
+#include "base/compiler_specific.h"
+
+namespace trace_event_internal {
+
+HeapProfilerScopedIgnore::HeapProfilerScopedIgnore() {}
+
+HeapProfilerScopedIgnore::~HeapProfilerScopedIgnore() {
+  if (UNLIKELY(
+          base::trace_event::AllocationContextTracker::capture_enabled())) {
+    // The corresponding begin_ignore_scope is defined in the definition of
+    // HEAP_PROFILER_SCOPED_IGNORE in the header.
+    base::trace_event::AllocationContextTracker::GetInstanceForCurrentThread()
+        ->end_ignore_scope();
+  }
+}
+
+}  // namespace trace_event_internal