mention firefox bug and add domContentLoadedStart/End

doc/howtos/howto-9.html

@@ -16,7 +16,7 @@ <h1>Boomerang Howto #9: Collect performance data from the Navigation Timing API<
 <ul>
 <li>Chrome 6+</li>
 <li>Internet Explorer 9+</li>
-<li><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=570341">Coming soon to Firefox</a></li>
+<li>Firefox 7+ (<strong>note</strong> that a bug in Firefox 7 and 8 reports the incorrect time for navigationStart.  Use unloadEventStart or fetchStart for a close proximation.)</li>
 </ul>
 
 <p>The navtiming.js plugin doesn't require any configuration options as it simply
@@ -58,7 +58,8 @@ <h1>Boomerang Howto #9: Collect performance data from the Navigation Timing API<
 <tr><td><code>nt_res_end</code></td><td><code>window.performance.timing.responseEnd</code></td></tr>
 <tr><td><code>nt_domloading</code></td><td><code>window.performance.timing.domLoading</code></td></tr>
 <tr><td><code>nt_domint</code></td><td><code>window.performance.timing.domInteractive</code></td></tr>
-<tr><td><code>nt_domcontloaded</code></td><td><code>window.performance.timing.domContentLoaded</code></td></tr>
+<tr><td><code>nt_domcontloaded_st</code></td><td><code>window.performance.timing.domContentLoadedStart</code></td></tr>
+<tr><td><code>nt_domcontloaded_end</code></td><td><code>window.performance.timing.domContentLoadedEnd</code></td></tr>
 <tr><td><code>nt_domcomp</code></td><td><code>window.performance.timing.domComplete</code></td></tr>
 <tr><td><code>nt_load_st</code></td><td><code>window.performance.timing.loadEventStart</code></td></tr>
 <tr><td><code>nt_load_end</code></td><td><code>window.performance.timing.loadEventEnd</code></td></tr>