s/precendence/precedence/

chrome/common/extensions/docs/templates/intros/power.html

 <h2 id="usage">Usage</h2>
 
 <p>
 By default,
 operating systems dim the screen when users are inactive
 and eventually suspend the system.
 With the power API,
 an app or extension can keep the system awake.
 </p>
 
 <p>
 Using this API,
 you can specify the
 $(ref:Level) to which power management is disabled.
 The <code>"system"</code> level keeps the system active,
 but allows the screen to be dimmed or turned off.
 For example,
 a communication app can continue to receive messages
 while the screen is off.
 The <code>"display"</code> level keeps the screen and system active.
 E-book and presentation apps, for example,
 can keep the screen and system active
 while users read.
 </p>
 
 <p>
 When a user has more than one app or extension active,
 each with its own power level,
 the highest-precedence level takes effect;
-<code>"display"</code> always takes precendence
+<code>"display"</code> always takes precedence
 over <code>"system"</code>.
 For example,
 if app A asks for <code>"system"</code> power management,
 and app B asks for <code>"display"</code>,
 <code>"display"</code> is used until app B
 is unloaded or releases its request.
 If app A is still active,
 <code>"system"</code> is then used.
 </p>