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

content/public/common/content_client.h

Index: content/public/common/content_client.h
diff --git a/content/public/common/content_client.h b/content/public/common/content_client.h
index 9b9cebac720c5ff42fb525d284523ce238dbc429..607abc2846f032d5e759ec66c3c142c59454063c 100644
--- a/content/public/common/content_client.h
+++ b/content/public/common/content_client.h
@@ -12,6 +12,7 @@
 #include "base/basictypes.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_piece.h"
+#include "base/trace_event/trace_event_impl.h"
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "ui/base/layout.h"
@@ -141,6 +142,9 @@ class CONTENT_EXPORT ContentClient {
   virtual void AddSecureSchemesAndOrigins(std::set<std::string>* schemes,
                                           std::set<GURL>* origins) {}
 
+  virtual base::trace_event::TraceEvent::EventFilterPredicate
+      GetTraceEventFilterPredicate() const;
+
  private:
   friend class ContentClientInitializer;  // To set these pointers.
   friend class InternalTestInitializer;