chrome/common/extensions/docs/templates/articles/settings_override.html

<h1>Settings Overrides</h1>

<p>
Settings overrides are a way for extensions to override selected Chrome settings.
</p>

<h2 id="others">Homepage, Search Provider, and Startup Pages</h2>
<p>
Here is an example how <a href="#homepage">homepage</a>, <a
href="#search_provider">search provider</a> and <a href="#startup_pages">startup
pages</a> can be modified in the <a href="manifest">extension
manifest</a>. Web sites used in the settings API must be
<a href="https://support.google.com/webmasters/answer/35179">verified</a> (via
Webmaster Tools) as being associated with that item in the Chrome Web Store.
Note that if you verify ownership for a domain (for example, http://example.com)
you can use any subdomain or page (for example, http://app.example.com or
http://example.com/page.html) within your extension.</p>

<pre>{
  "name": "My extension",
  ...
  "chrome_settings_overrides": {
    "homepage": "http://www.homepage.com",
    "search_provider": {
        "name": "name.__MSG_url_domain__",
        "keyword": "keyword.__MSG_url_domain__",
        "search_url": "http://www.foo.__MSG_url_domain__/s?q={searchTerms}",
        "favicon_url": "http://www.foo.__MSG_url_domain__/favicon.ico",
        "suggest_url": "http://www.foo.__MSG_url_domain__/suggest?q={searchTerms}",
        "instant_url": "http://www.foo.__MSG_url_domain__/instant?q={searchTerms}",
        "image_url": "http://www.foo.__MSG_url_domain__/image?q={searchTerms}",
        "search_url_post_params": "search_lang=__MSG_url_domain__",
        "suggest_url_post_params": "suggest_lang=__MSG_url_domain__",
        "instant_url_post_params": "instant_lang=__MSG_url_domain__",
        "image_url_post_params": "image_lang=__MSG_url_domain__",
        "alternate_urls": [
          "http://www.moo.__MSG_url_domain__/s?q={searchTerms}",
          "http://www.noo.__MSG_url_domain__/s?q={searchTerms}"
        ],
        "encoding": "UTF-8",
        "is_default": true
    },
    "startup_pages": ["http://www.startup.com"]
   },
   "default_locale": "de",
   ...
}</pre>

<p class="note">
<b>Note:</b> Settings overrides for <code>homepage</code>,
<code>search_provider</code>, and <code>startup_pages</code> are only enabled
in the Chrome Dev release.</p>

<h2 id="customizing">Customizing values</h2>
<p>Values in the manifest can be customized in the following ways:</p>
<ul>
  <li>
  All values of the <code>search_provider</code>, <code>homepage</code> and
  <code>startup_pages</code> properties can be localized using the
  $(ref:i18n chrome.i18n API).
  </li>
  <li>
  For <a href="http://developer.chrome.com/extensions/external_extensions">external extensions</a>,
  the <code>search_provider</code>, <code>homepage</code> and
  <code>startup_pages</code> URL values can be parametrized using a registry key.
  A new registry entry should be created next to the "update_url" key (see
  instructions <a href="http://developer.chrome.com/extensions/external_extensions#registry">here</a>).
  The value name is "install_parameter", the value data is an arbitrary string:
  <pre>{
    "update_url": "https://clients2.google.com/service/update2/crx",
    "install_parameter": "Value"
  }</pre>
  All occurrences of the substring "__PARAM__" in the manifest URLs will be
  substituted with the "install_parameter" value. If “install_parameter” is
  absent, occurrences of "__PARAM__" are removed. Note that "__PARAM__" cannot
  be part of the hostname. It needs to occur after the first '/' in the URL.
  </li>
</ul>

<h2 id="reference">Reference</h2>
<p>
An extension can override one or more of the following properties in the
manifest:
</p>

<ul>
{{#f:apis.manifestTypes.byName.ChromeSettingsOverrides.properties}}
  <li>
  <p id="{{f.name}}"><b><code>{{f.name}}</code> ({{+partials.variable_type type:f/}})</b></p>
  <p>{{f.description}}</p>
  {{?f.properties}}
    <table>
    <tr><th>Type</th><th>Attribute</th><th>Description</th></tr>
    {{+partials.type_item
       title:f.strings.properties
       display_name:display_name
       items:f.properties
       item_partial:(partials.parameter_full hideParamTOC:true)/}}
    </table>
  {{/}}
{{/}}
</ul>