[tracing] Use same code path for category filtering for recording and event filtering

base/trace_event/trace_config_category_filter.h

Index: base/trace_event/trace_config_category_filter.h
diff --git a/base/trace_event/trace_config_category_filter.h b/base/trace_event/trace_config_category_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..df8c3a5b2a70d3e7a5d4762fa79fa20035905f18
--- /dev/null
+++ b/base/trace_event/trace_config_category_filter.h
@@ -0,0 +1,86 @@
+// 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.
+
+#ifndef BASE_TRACE_EVENT_TRACE_CONFIG_CATEGORY_FILTER_H_
+#define BASE_TRACE_EVENT_TRACE_CONFIG_CATEGORY_FILTER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/strings/string_piece.h"
+#include "base/values.h"
+
+namespace base {
+namespace trace_event {
+
+// Configuration of categories enabled and disabled in TraceConfig.
+class BASE_EXPORT TraceConfigCategoryFilter {
+ public:
+  using StringList = std::vector<std::string>;
+
+  TraceConfigCategoryFilter();
+  TraceConfigCategoryFilter(const TraceConfigCategoryFilter& other);
+  ~TraceConfigCategoryFilter();
+
+  TraceConfigCategoryFilter& operator=(const TraceConfigCategoryFilter& rhs);
+
+  // Initializes from category filter string. See TraceConfig constructor for
+  // description of how to write category filter string.
+  void InitializeFromString(const StringPiece& category_filter_string);
+
+  // Initializes TraceConfigCategoryFilter object from the config dictionary.
+  void InitializeFromConfigDict(const DictionaryValue& dict);
+
+  // Merges this with category filter config.
+  void Merge(const TraceConfigCategoryFilter& config);
+  void Clear();
+
+  // Returns true if at least one category in the list is enabled by this
+  // trace config. This is used to determine if the category filters are
+  // enabled in the TRACE_* macros.
+  bool IsCategoryGroupEnabled(const char* category_group_name) const;
+
+  // Returns true if the category is enabled according to this trace config.
+  // This tells whether a category is enabled from the TraceConfig's
+  // perspective. Please refer to IsCategoryGroupEnabled() to determine if a
+  // category is enabled from the tracing runtime's perspective.
+  bool IsCategoryEnabled(const char* category_name) const;
+
+  void ToDict(DictionaryValue* dict) const;
+
+  std::string ToFilterString() const;
+
+  // Returns true if category name is a valid string.
+  static bool IsCategoryNameAllowed(StringPiece str);
+
+  const StringList& included_categories() const { return included_categories_; }
+  const StringList& excluded_categories() const { return excluded_categories_; }
+  const StringList& synthetic_delays() const { return synthetic_delays_; }
+
+ private:
+  void SetCategoriesFromIncludedList(const ListValue& included_list);
+  void SetCategoriesFromExcludedList(const ListValue& excluded_list);
+  void SetSyntheticDelaysFromList(const ListValue& list);
+
+  void AddCategoriesToDict(const StringList& categories,
+                           const char* param,
+                           DictionaryValue* dict) const;
+
+  void WriteCategoryFilterString(const StringList& values,
+                                 std::string* out,
+                                 bool included) const;
+  void WriteCategoryFilterString(const StringList& delays,
+                                 std::string* out) const;
+
+  StringList included_categories_;
+  StringList disabled_categories_;
+  StringList excluded_categories_;
+  StringList synthetic_delays_;
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_TRACE_CONFIG_CATEGORY_FILTER_H_