Add DocumentTiming metrics for "time to first text paint"

Source/web/WebPerformance.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 153 matching lines @@
 double WebPerformance::loadEventEnd() const
 {
     return millisecondsToSeconds(m_private->timing()->loadEventEnd());
 }
 
 double WebPerformance::firstLayout() const
 {
     return millisecondsToSeconds(m_private->timing()->firstLayout());
 }
 
+double WebPerformance::firstNonBlankText() const
+{
+    return millisecondsToSeconds(m_private->timing()->firstNonBlankText());
+}
+
+double WebPerformance::firstCustomFontText() const
+{
+    return millisecondsToSeconds(m_private->timing()->firstCustomFontText());
+}
+
 WebPerformance::WebPerformance(const PassRefPtrWillBeRawPtr<Performance>& performance)
     : m_private(performance)
 {
 }
 
 WebPerformance& WebPerformance::operator=(const PassRefPtrWillBeRawPtr<Performance>& performance)
 {
     m_private = performance;
     return *this;
 }
 
 } // namespace blink