Added a whitelist for trace events that are known to be PII-less.

components/tracing/child_trace_message_filter.cc

Index: components/tracing/child_trace_message_filter.cc
diff --git a/components/tracing/child_trace_message_filter.cc b/components/tracing/child_trace_message_filter.cc
index 3dd1223d643140e67ec30bb63695cd464107d134..c9ddeb6be5e901e32f79974a2d574bf0e3535c74 100644
--- a/components/tracing/child_trace_message_filter.cc
+++ b/components/tracing/child_trace_message_filter.cc
@@ -8,6 +8,7 @@
 #include "base/trace_event/trace_event.h"
 #include "components/tracing/child_memory_dump_manager_delegate_impl.h"
 #include "components/tracing/tracing_messages.h"
+#include "content/public/common/tracing_utils.h"
 #include "ipc/ipc_channel.h"
 
 using base::trace_event::TraceLog;
@@ -75,6 +76,13 @@ void ChildTraceMessageFilter::OnBeginTracing(
       base::trace_event::CategoryFilter(category_filter_str),
       base::trace_event::TraceLog::RECORDING_MODE,
       trace_options);
+
+#if !defined(__native_client__)
+  if (trace_options.enable_args_whitelist) {
+    TraceLog::GetInstance()->SetEventFilterPredicate(
+        content::GetTraceEventFilterPredicate());
+  }
+#endif
 }
 
 void ChildTraceMessageFilter::OnEndTracing() {
@@ -98,6 +106,13 @@ void ChildTraceMessageFilter::OnEnableMonitoring(
       base::trace_event::CategoryFilter(category_filter_str),
       base::trace_event::TraceLog::MONITORING_MODE,
       trace_options);
+
+#if !defined(__native_client__)
+  if (trace_options.enable_args_whitelist) {
+    TraceLog::GetInstance()->SetEventFilterPredicate(
+        content::GetTraceEventFilterPredicate());
+  }
+#endif
 }
 
 void ChildTraceMessageFilter::OnDisableMonitoring() {