memory-infra: Add SUMMARY_ONLY MemoryDumpType

base/trace_event/memory_tracing_observer.cc

 // Copyright 2017 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/memory_tracing_observer.h"
 
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace base {
@@ skipping 53 matching lines @@
 }
 
 bool MemoryTracingObserver::AddDumpToTraceIfEnabled(
     const MemoryDumpRequestArgs* req_args,
     const ProcessId pid,
     const ProcessMemoryDump* process_memory_dump) {
   // If tracing has been disabled early out to avoid the cost of serializing the
   // 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;
 
   std::unique_ptr<TracedValue> traced_value(new TracedValue);
   process_memory_dump->AsValueInto(traced_value.get());
   traced_value->SetString("level_of_detail", MemoryDumpLevelOfDetailToString(
                                                  req_args->level_of_detail));
   const char* const event_name = MemoryDumpTypeToString(req_args->dump_type);
 
   std::unique_ptr<ConvertableToTraceFormat> event_value(
       std::move(traced_value));
   TRACE_EVENT_API_ADD_TRACE_EVENT_WITH_PROCESS_ID(
       TRACE_EVENT_PHASE_MEMORY_DUMP,
       TraceLog::GetCategoryGroupEnabled(MemoryDumpManager::kTraceCategory),
       event_name, trace_event_internal::kGlobalScope, dump_guid, pid,
       kTraceEventNumArgs, kTraceEventArgNames, kTraceEventArgTypes,
       nullptr /* arg_values */, &event_value, TRACE_EVENT_FLAG_HAS_ID);
 
   return true;
 }
 
 }  // namespace trace_event
 }  // namespace base