[tracing] Don't register tracing-related allocations.

base/trace_event/malloc_dump_provider.cc

Index: base/trace_event/malloc_dump_provider.cc
diff --git a/base/trace_event/malloc_dump_provider.cc b/base/trace_event/malloc_dump_provider.cc
index c09470befae184cd5dc38c87fc9e29d00d04c535..4683694d6bb60dc15a59b544dcadf639a7464e84 100644
--- a/base/trace_event/malloc_dump_provider.cc
+++ b/base/trace_event/malloc_dump_provider.cc
@@ -297,7 +297,10 @@ void MallocDumpProvider::InsertAllocation(void* address, size_t size) {
   auto* tracker = AllocationContextTracker::GetInstanceForCurrentThread();
   if (!tracker)
     return;
-  AllocationContext context = tracker->GetContextSnapshot();
+
+  AllocationContext context;
+  if (!tracker->GetContextSnapshot(&context))
+    return;
 
   AutoLock lock(allocation_register_lock_);
   if (!allocation_register_)