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

chrome/common/trace_event_args_whitelist.h

Index: chrome/common/trace_event_args_whitelist.h
diff --git a/chrome/common/trace_event_args_whitelist.h b/chrome/common/trace_event_args_whitelist.h
new file mode 100644
index 0000000000000000000000000000000000000000..ed89245a04649033e4fa4a978c91ecba3c443ca9
--- /dev/null
+++ b/chrome/common/trace_event_args_whitelist.h
@@ -0,0 +1,15 @@
+// Copyright 2015 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 CHROME_COMMON_TRACE_EVENT_ARGS_WHITELIST_H_
+#define CHROME_COMMON_TRACE_EVENT_ARGS_WHITELIST_H_
+
+namespace chrome {
+
+bool IsTraceEventArgsWhitelisted(const char* category_group_name,
+                                 const char* event_name);
+
+}  // namespace chrome
+
+#endif  // CHROME_COMMON_TRACE_EVENT_ARGS_WHITELIST_H_