tracing: split trace event filter classes out of TraceLog

base/trace_event/trace_event_filter_test_utils.h

+// Copyright 2016 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 BASE_TRACE_EVENT_TRACE_EVENT_FILTER_TEST_UTILS_H_
+#define BASE_TRACE_EVENT_TRACE_EVENT_FILTER_TEST_UTILS_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "base/trace_event/trace_event_filter.h"
+
+namespace base {
+namespace trace_event {
+
+class TestEventFilter : public TraceEventFilter {
+ public:
+  struct HitsCounter {
+    HitsCounter();
+    ~HitsCounter();
+    void Reset();
+    size_t filter_trace_event_hit_count;
+    size_t end_event_hit_count;
+  };
+
+  static const char kName[];
+
+  // Factory method for TraceLog::SetFilterFactoryForTesting().
+  static std::unique_ptr<TraceEventFilter> Factory(
+      const std::string& predicate_name);
+
+  TestEventFilter();
+  ~TestEventFilter() override;
+
+  // TraceEventFilter implementation.
+  bool FilterTraceEvent(const TraceEvent& trace_event) const override;
+  void EndEvent(const char* category_name, const char* name) const override;
+
+  static void set_filter_return_value(bool value) {
+    filter_return_value_ = value;
+  }
+
+ private:
+  static bool filter_return_value_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestEventFilter);
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_TRACE_EVENT_FILTER_TEST_UTILS_H_