memory-infra: Add SUMMARY_ONLY MemoryDumpType

base/trace_event/memory_tracing_observer.cc

Index: base/trace_event/memory_tracing_observer.cc
diff --git a/base/trace_event/memory_tracing_observer.cc b/base/trace_event/memory_tracing_observer.cc
index 3130b205f89c25f70f30c8dd11e0c02558dd3a1c..85d7e98684d71cde902a5677e3a1efb2ce48ed1b 100644
--- a/base/trace_event/memory_tracing_observer.cc
+++ b/base/trace_event/memory_tracing_observer.cc
@@ -71,6 +71,10 @@ bool MemoryTracingObserver::AddDumpToTraceIfEnabled(
   // dump then ignoring the result.
   if (!IsMemoryInfraTracingEnabled())
     return false;
+  // Some dumps are requested just to cacluate the summary. These shouldn't be
+  // added to the trace to avoid confusing trace consumers.
+  if (req_args->dump_type == MemoryDumpType::SUMMARY_ONLY)
+    return false;
 
   const uint64_t dump_guid = req_args->dump_guid;