Integrate ETW with VLOG logging.

base/vlog.h

 // Copyright (c) 2010 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_VLOG_H_
 #define BASE_VLOG_H_
 #pragma once
 
 #include <cstddef>
 #include <string>
@@ skipping 10 matching lines @@
   // |v_switch| gives the default maximal active V-logging level; 0 is
   // the default.  Normally positive values are used for V-logging
   // levels.
   //
   // |vmodule_switch| gives the per-module maximal V-logging levels to
   // override the value given by |v_switch|.
   // E.g. "my_module=2,foo*=3" would change the logging level for all
   // code in source files "my_module.*" and "foo*.*" ("-inl" suffixes
   // are also disregarded for this matching).
   //
+  // |log_severity| points to an int that stores the log level. If a valid
+  // |v_switch| is provided, it will set the log level, and the default
+  // vlog severity will be read from there..
+  //
   // Any pattern containing a forward or backward slash will be tested
   // against the whole pathname and not just the module.  E.g.,
   // "*/foo/bar/*=2" would change the logging level for all code in
   // source files under a "foo/bar" directory.
   VlogInfo(const std::string& v_switch,
-           const std::string& vmodule_switch);
+           const std::string& vmodule_switch,
+           int* min_log_level);
   ~VlogInfo();
 
   // Returns the vlog level for a given file (usually taken from
   // __FILE__).
-  int GetVlogLevel(const base::StringPiece& file);
+  int GetVlogLevel(const base::StringPiece& file) const;
 
   static const int kDefaultVlogLevel;
 
  private:
+  void SetMaxVlogLevel(int level);
+  int GetMaxVlogLevel() const;
+
   // VmodulePattern holds all the information for each pattern parsed
   // from |vmodule_switch|.
   struct VmodulePattern {
     enum MatchTarget { MATCH_MODULE, MATCH_FILE };
 
     explicit VmodulePattern(const std::string& pattern);
 
     VmodulePattern();
 
     std::string pattern;
     int vlog_level;
     MatchTarget match_target;
   };
 
-  int max_vlog_level_;
   std::vector<VmodulePattern> vmodule_levels_;
+  int* min_log_level_;
 
   DISALLOW_COPY_AND_ASSIGN(VlogInfo);
 };
 
 // Returns true if the string passed in matches the vlog pattern.  The
 // vlog pattern string can contain wildcards like * and ?.  ? matches
 // exactly one character while * matches 0 or more characters.  Also,
 // as a special case, a / or \ character matches either / or \.
 //
 // Examples:
 //   "kh?n" matches "khan" but not "khn" or "khaan"
 //   "kh*n" matches "khn", "khan", or even "khaaaaan"
 //   "/foo\bar" matches "/foo/bar", "\foo\bar", or "/foo\bar"
 //     (disregarding C escaping rules)
 bool MatchVlogPattern(const base::StringPiece& string,
                       const base::StringPiece& vlog_pattern);
 
 }  // namespace logging
 
 #endif  // BASE_VLOG_H_