Fix backwards WebRTC-in-Chromium override and expose Chromium logging setup

third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h

Index: third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h
diff --git a/third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h b/third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h
index 3a29c3afe961b99eb8985e7b768ca4285730b9a4..dad634c8072b4dbcc46091db03092a9d34c59eb8 100644
--- a/third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h
+++ b/third_party/webrtc_overrides/webrtc/base/diagnostic_logging.h
@@ -49,15 +49,21 @@ std::string ErrorName(int err, const ConstantLabel* err_table);
 //   in debug builds.
 //  LS_WARNING: Something that may warrant investigation.
 //  LS_ERROR: Something that should not have occurred.
+//  LS_NONE: A level < LS_ERROR, used to disable logging.
 // Note that LoggingSeverity is mapped over to chromiums verbosity levels where
 // anything lower than or equal to the current verbosity level is written to
 // file which is the opposite of logging severity in libjingle where higher
 // severity numbers than or equal to the current severity level are written to
 // file. Also, note that the values are explicitly defined here for convenience
 // since the command line flag must be set using numerical values.
+//
+// LS_NONE is present so we can LogToDebug(LS_NONE) i.e. for ordinal
+// comparisons with other log levels.
+//
 // TODO(tommi): To keep things simple, we should just use the same values for
 // these constants as Chrome does.
-enum LoggingSeverity { LS_ERROR = 1,
+enum LoggingSeverity { LS_NONE = 0,
+                       LS_ERROR = 1,
                        LS_WARNING = 2,
                        LS_INFO = 3,
                        LS_VERBOSE = 4,
@@ -130,7 +136,7 @@ class LogMultilineState {
 
 class LogMessage {
  public:
-  static void LogToDebug(int min_sev);
+  static void LogToDebug(LoggingSeverity min_sev);
 };
 
 // When possible, pass optional state variable to track various data across