Add settings UI for managing defaults

chrome/browser/resources/options2/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="cookies_tab_label"></h3>
       <div>
         <div class="radio">
           <label>
@@ skipping 231 matching lines @@
           <label>
             <input type="radio" name="mouselock" value="block">
             <span i18n-content="mouselock_block"></span>
           </label>
         </div>
         <button class="exceptions-list-button" contentType="mouselock"
             i18n-content="manage_exceptions"></button>
       </div>
     </section>
     <!-- Intent registration filter -->
+
     <section>
-      <h3 i18n-content="webIntentsTabLabel" class="content-settings-header">
-      </h3>
-      <div class="checkbox">
-        <label>
-          <input pref="webintents.enabled" type="checkbox">
-          <span i18n-content="allowWebIntents"></span>
-        </label>
+      <h3 i18n-content="web_intents_tab_label"

[csilv, 2012/08/09 18:18:04]

Although this rule isn't followed consistently, we prefer camelCase for
i18n-content tags
(http://dev.chromium.org/developers/web-development-style-guide).  Let's follow
the rule, someday one of us will do a global fix for the others.

+          class="content-settings-header"></h3>
+      <div>
+        <div class="checkbox">
+          <label>
+            <input pref="webintents.enabled" type="checkbox">
+            <span i18n-content="web_intents_enabled"></span>
+          </label>
+        </div>
+        <button id="manage-web-intents-defaults-button"
+            contentType="intents"
+            i18n-content="web_intents_defaults_button_title"></button>
       </div>
     </section>
+
     <!-- Pepper Flash camera and microphone filter -->
     <section id="pepper-flash-cameramic-section" class="pepper-flash-settings">
       <h3 i18n-content="pepperFlashCameramicTabLabel"></h3>
       <div>
         <div class="radio">
           <label>
             <input type="radio" name="pepper-flash-cameramic" value="ask">
             <span i18n-content="pepperFlashCameramicAsk"></span>
           </label>
         </div>
@@ skipping 53 matching lines @@
             i18n-content="manageGalleriesButton"></button>
       </div>
     </section>
   </div>
   <div class="action-area">
     <div class="button-strip">
       <button id="content-settings-overlay-confirm" i18n-content="ok"></button>
     </div>
   </div>
 </div>