Plugin Power Saver: Replace all "plug-in" with "plugin" for consistency.

chrome/browser/resources/options/content_settings.html

 <div id="content-settings-page" class="page" hidden>
   <div class="close-button"></div>
   <h1 i18n-content="contentSettingsPage"></h1>
   <div class="content-area">
     <!-- Cookie filter tab contents -->
     <section>
       <h3 i18n-content="cookiesTabLabel"></h3>
       <div class="replace-with-website-settings">
         <div class="radio controlled-setting-with-label">
           <label>
@@ skipping 154 matching lines @@
                 class="handler-radio">
             <span i18n-content="handlers_block"></span>
           </label>
         </div>
         <div class="settings-row">
           <button id="manage-handlers-button" contentType="handlers"
               i18n-content="manage_handlers"></button>
         </div>
       </div>
     </section>
-    <!-- Plug-ins filter -->
+    <!-- Plugins filter -->
     <section>
       <h3 i18n-content="pluginsTabLabel"></h3>
       <div class="replace-with-website-settings">
         <div class="radio controlled-setting-with-label">
           <label>
             <input type="radio" name="plugins" value="allow">
             <span>
               <span i18n-content="pluginsAllow"></span>
               <span class="controlled-setting-indicator"
                   content-setting="plugins" value="allow"></span>
@@ skipping 480 matching lines @@
     </section>
   </div>
   <div class="action-area">
     <div class="button-strip">
       <button id="content-settings-overlay-confirm" class="default-button"
           i18n-content="done">
       </button>
     </div>
   </div>
 </div>