[tracing] Introduce "allowed_dump_modes" for memory dump config

content/browser/tracing/background_tracing_manager_impl.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 "content/browser/tracing/background_tracing_manager_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/json/json_writer.h"
@@ skipping 29 matching lines @@
   SCENARIO_ACTION_FAILED_LOWRES_CLOCK = 9,
   NUMBER_OF_BACKGROUND_TRACING_METRICS,
 };
 
 void RecordBackgroundTracingMetric(BackgroundTracingMetrics metric) {
   UMA_HISTOGRAM_ENUMERATION("Tracing.Background.ScenarioState", metric,
                             NUMBER_OF_BACKGROUND_TRACING_METRICS);
 }
 
 // Tracing enabled callback for BENCHMARK_MEMORY_LIGHT category preset.
-// TODO(ssid): Remove this when background tracing supports trace config strings
-// and memory-infra supports peak detection crbug.com/609935.
 void BenchmarkMemoryLight_TracingEnabledCallback() {
   base::trace_event::MemoryDumpManager::GetInstance()->RequestGlobalDump(
       base::trace_event::MemoryDumpType::EXPLICITLY_TRIGGERED,
       base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND);
 }
 
 }  // namespace
 
 BackgroundTracingManagerImpl::TracingTimer::TracingTimer(
     StartedFinalizingCallback callback) : callback_(callback) {
@@ skipping 340 matching lines @@
   if (requires_anonymized_data_)
     trace_config.EnableArgumentFilter();
 
   base::Closure tracing_enabled_callback;
   if (!tracing_enabled_callback_for_testing_.is_null()) {
     tracing_enabled_callback = tracing_enabled_callback_for_testing_;
   } else if (preset == BackgroundTracingConfigImpl::CategoryPreset::
                            BENCHMARK_MEMORY_LIGHT) {
     // On memory light mode, the periodic memory dumps are disabled and a single
     // memory dump is requested after tracing is enabled in all the processes.
+    // TODO(ssid): Remove this when background tracing supports trace config
+    // strings and memory-infra supports peak detection crbug.com/609935.
+    base::trace_event::TraceConfig::MemoryDumpConfig memory_config;
+    memory_config.allowed_dump_modes =
+        std::set<base::trace_event::MemoryDumpLevelOfDetail>(
+            {base::trace_event::MemoryDumpLevelOfDetail::BACKGROUND});
     trace_config.ResetMemoryDumpConfig(
         base::trace_event::TraceConfig::MemoryDumpConfig());

[Primiano Tucci (use gerrit), 2016/06/09 18:46:39]

ehm don't you have to pass memory_config here instead? 
This is what I said where I worry that we forget to plumb the traceconfig fully.

Can we add a cross-check? In the BenchmarkMemoryLight_TracingEnabledCallback can
we 
if (preset == MEMORY_LIGHT)
CHEKCK_FALSE(MDM::GetInstance::IsDumpModeAllowed(DETAILED)) 

[ssid, 2016/06/09 21:34:15]

Done.
Yeah I think this should be fixed when we can have trace config uploaded from
finch. we will have better control.

     tracing_enabled_callback =
         base::Bind(&BenchmarkMemoryLight_TracingEnabledCallback);
   }
 
   is_tracing_ = TracingController::GetInstance()->StartTracing(
       trace_config, tracing_enabled_callback);
   RecordBackgroundTracingMetric(RECORDING_ENABLED);
 }
 
 void BackgroundTracingManagerImpl::OnFinalizeStarted(
@@ skipping 124 matching lines @@
     case BackgroundTracingConfigImpl::CategoryPreset::BLINK_STYLE:
       return "blink_style";
     case BackgroundTracingConfigImpl::CategoryPreset::CATEGORY_PRESET_UNSET:
       NOTREACHED();
   }
   NOTREACHED();
   return "";
 }
 
 }  // namspace content