[tracing] Expose level of detail of memory dumps in the trace JSON

base/trace_event/memory_dump_manager.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/memory_dump_manager.h"
 
 #include <algorithm>
 
 #include "base/atomic_sequence_num.h"
 #include "base/command_line.h"
@@ skipping 349 matching lines @@
     scoped_ptr<ProcessMemoryDumpAsyncState> pmd_async_state) {
   if (!pmd_async_state->task_runner->BelongsToCurrentThread()) {
     scoped_refptr<SingleThreadTaskRunner> task_runner =
         pmd_async_state->task_runner;
     task_runner->PostTask(FROM_HERE,
                           Bind(&MemoryDumpManager::FinalizeDumpAndAddToTrace,
                                Passed(pmd_async_state.Pass())));
     return;
   }
 
-  scoped_refptr<ConvertableToTraceFormat> event_value(new TracedValue());
-  pmd_async_state->process_memory_dump.AsValueInto(
-      static_cast<TracedValue*>(event_value.get()));
+  TracedValue* traced_value = new TracedValue();
+  scoped_refptr<ConvertableToTraceFormat> event_value(traced_value);
+  pmd_async_state->process_memory_dump.AsValueInto(traced_value);
+  traced_value->SetString("level_of_detail",
+                          MemoryDumpLevelOfDetailToString(
+                              pmd_async_state->req_args.level_of_detail));
   const char* const event_name =
       MemoryDumpTypeToString(pmd_async_state->req_args.dump_type);
 
   TRACE_EVENT_API_ADD_TRACE_EVENT(
       TRACE_EVENT_PHASE_MEMORY_DUMP,
       TraceLog::GetCategoryGroupEnabled(kTraceCategory), event_name,
       pmd_async_state->req_args.dump_guid, kTraceEventNumArgs,
       kTraceEventArgNames, kTraceEventArgTypes, nullptr /* arg_values */,
       &event_value, TRACE_EVENT_FLAG_HAS_ID);
 
@@ skipping 120 matching lines @@
       next_dump_provider(next_dump_provider),
       callback(callback),
       task_runner(MessageLoop::current()->task_runner()) {
 }
 
 MemoryDumpManager::ProcessMemoryDumpAsyncState::~ProcessMemoryDumpAsyncState() {
 }
 
 }  // namespace trace_event
 }  // namespace base