Re-land first pass BackgroundTracingManager.

content/public/browser/background_tracing_config.h

+// 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.
+
+#ifndef CONTENT_PUBLIC_BROWSER_BACKGROUND_TRACING_CONFIG_H_
+#define CONTENT_PUBLIC_BROWSER_BACKGROUND_TRACING_CONFIG_H_
+
+#include "base/memory/ref_counted_memory.h"
+#include "base/trace_event/trace_event_impl.h"
+#include "base/values.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// BackgroundTracingConfig is passed to the BackgroundTracingManager to
+// setup the trigger rules used to enable/disable background tracing.
+class CONTENT_EXPORT BackgroundTracingConfig
+    : public base::RefCountedThreadSafe<BackgroundTracingConfig> {
+ public:
+  enum Mode {

[no sievers, 2015/05/11 21:13:27]

each interface/struct/enum should be in a separate file
(https://www.chromium.org/developers/content-module/content-api)

[shatch, 2015/05/12 21:00:05]

Yeah I saw that rule but wasn't clear if that also extended to enums/structs
declared in classes. A quick search through content/public found about 16
instances of enums declared in classes, so that rule didn't seem to apply here,
ie:

content/public/browser/navigation_controller.h
content/public/browser/power_save_blocker.h


I don't mind doing it but moving each enum and struct to a separate file will
add 8 new files to this CL. Do you still want these moved or is this ok?

+    PREEMPTIVE_TRACING_MODE,
+    REACTIVE_TRACING_MODE,
+  };
+  enum CategoryPreset {
+    BENCHMARK,
+    BENCHMARK_DEEP,
+  };
+
+  Mode mode() const;
+
+  static BackgroundTracingConfig* FromDict(const base::DictionaryValue* dict);
+  void IntoDict(base::DictionaryValue* dict);
+
+ protected:
+  friend class base::RefCountedThreadSafe<BackgroundTracingConfig>;
+
+  BackgroundTracingConfig(Mode mode);
+  virtual ~BackgroundTracingConfig();
+
+  Mode mode_;
+};
+
+// BackgroundTracingPreemptiveConfig holds trigger rules for use during
+// preemptive tracing. Tracing will be enabled immediately, and whenever
+// a trigger occurs, the trace will be finalized.
+class CONTENT_EXPORT BackgroundTracingPreemptiveConfig
+    : public BackgroundTracingConfig {
+ public:
+  BackgroundTracingPreemptiveConfig();
+
+  enum RuleType {
+    MONITOR_AND_DUMP_WHEN_TRIGGER_NAMED,
+    MONITOR_AND_DUMP_WHEN_SPECIFIC_HISTOGRAM_AND_VALUE,
+    MONITOR_AND_DUMP_WHEN_BROWSER_STARTED,
+  };
+  struct HistogramTriggerInfo {
+    std::string histogram_name_to_trigger_on;
+    int histogram_bin_to_trigger_on;
+  };
+  struct NamedTriggerInfo {
+    std::string trigger_name;
+  };
+  struct MonitoringRule {
+    RuleType type;
+    HistogramTriggerInfo histogram_trigger_info;
+    NamedTriggerInfo named_trigger_info;
+  };
+
+  void AddHistogramTriggerRule(const std::string& histogram_name,
+                               int histogram_bin);
+  void AddNamedTriggerRule(const std::string& trigger_name);
+
+  CategoryPreset category_preset() const;
+  const std::vector<MonitoringRule>& configs() const;
+
+  static BackgroundTracingPreemptiveConfig* FromDict(
+      const base::DictionaryValue* dict);
+  void AsDict(base::DictionaryValue* dict);
+
+ protected:
+  ~BackgroundTracingPreemptiveConfig() override;
+
+  std::vector<MonitoringRule> configs_;
+  CategoryPreset category_preset_;
+};
+
+// BackgroundTracingReactiveConfig holds trigger rules for use during
+// reactive tracing. Tracing will be not be enabled immediately, rather
+// the BackgroundTracingManager will wait for a trigger to occur, and
+// enable tracing at that point. Tracing will be finalized later, either
+// after some time has elapsed or the trigger occurs again.
+class CONTENT_EXPORT BackgroundTracingReactiveConfig
+    : public BackgroundTracingConfig {
+ public:
+  BackgroundTracingReactiveConfig();
+
+  enum RuleType { TRACE_ON_TRIGGER_UNTIL_10S_OR_NEXT_TRIGGER_OR_FULL };
+  struct TracingRule {
+    RuleType type;
+    std::string trigger_name;
+    CategoryPreset category_preset;
+  };
+
+  void AddTracingRule(RuleType rule_type,
+                      const char* trigger_name,
+                      CategoryPreset category_preset);
+
+  static BackgroundTracingReactiveConfig* FromDict(
+      const base::DictionaryValue* dict);
+  void AsDict(base::DictionaryValue* dict);
+
+ protected:
+  ~BackgroundTracingReactiveConfig() override;
+
+  std::vector<TracingRule> configs;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_BACKGROUND_TRACING_CONFIG_H_