Set the content/ trace event PII whitelist to be the arg-filtering predicate in TraceLog

base/trace_event/trace_event_impl.h

Index: base/trace_event/trace_event_impl.h
diff --git a/base/trace_event/trace_event_impl.h b/base/trace_event/trace_event_impl.h
index bfbbefa0158e3b6977ceb401c0f3ed6b6d3a1e86..30b2a63df2ddfe732a0f3930e81a033143428d50 100644
--- a/base/trace_event/trace_event_impl.h
+++ b/base/trace_event/trace_event_impl.h
@@ -386,12 +386,14 @@ struct BASE_EXPORT TraceOptions {
   TraceOptions()
       : record_mode(RECORD_UNTIL_FULL),
         enable_sampling(false),
-        enable_systrace(false) {}
+        enable_systrace(false),
+        enable_args_whitelist(false) {}
 
   explicit TraceOptions(TraceRecordMode record_mode)
       : record_mode(record_mode),
         enable_sampling(false),
-        enable_systrace(false) {}
+        enable_systrace(false),
+        enable_args_whitelist(false) {}
 
   // |options_string| is a comma-delimited list of trace options.
   // Possible options are: "record-until-full", "record-continuously",
@@ -422,6 +424,7 @@ struct BASE_EXPORT TraceOptions {
   TraceRecordMode record_mode;
   bool enable_sampling;
   bool enable_systrace;
+  bool enable_args_whitelist;
 };
 
 struct BASE_EXPORT TraceLogStatus {
@@ -752,6 +755,7 @@ class BASE_EXPORT TraceLog {
   static const InternalTraceOptions kInternalEchoToConsole;
   static const InternalTraceOptions kInternalEnableSampling;
   static const InternalTraceOptions kInternalRecordAsMuchAsPossible;
+  static const InternalTraceOptions kInternalEnableArgsWhitelist;
 
   // This lock protects TraceLog member accesses (except for members protected
   // by thread_info_lock_) from arbitrary threads.