Introduces an additional extension loader that load extra extensions based on per-extension json fi…

chrome/common/extensions/docs/static/external_extensions.html

 <div id="pageData-name" class="pageData">Other Deployment Options</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 Usually, users install their own extensions.
 But sometimes you might want an extension
 to be installed automatically.
 Here are two typical cases:
 </p>
 
 <ul>
   <li>
     An extension is associated with some other software,
     and the extension should be installed
     whenever the user installs that other software.
     The extension could also be uninstalled
     when the user removes that other software.
   </li>
   <li>
     A network admin wants to install the same extensions
     throughout the company.
   </li>
 </ul>
 
 <p>
 An extension that's installed automatically is known as an
 <em>external extension</em>.
-Google Chrome supports two ways of
+Google Chrome supports three ways of
 installing external extensions:
 </p>
 
 <ul>
   <li> Using a preferences JSON file </li>
   <li> Using the Windows registry (Windows only) </li>
+  <li> Using per-extension preference files (Linux only) </li>
 </ul>
 
 <p>
-Both ways support installing an extension from a <code>.crx</code> extension
+Each method supports installing an extension from a <code>.crx</code> extension
 file on the user's computer.  The preferences JSON file also supports installing
 an extension hosted at an
 <a href="autoupdate.html#H2-1">update URL</a>.
 See <a href="hosting.html">hosting</a> for details on hosting an extension.
 </p>
 
 <h2 id="prereqs">Before you begin</h2>
 
 <p>
 First, package a
@@ skipping 164 matching lines @@
 <ul>
   <li>path: <code>\\server\share\extension.crx</code> </li>
   <li>version: <code>1.0</code> </li>
 </ul>
 </li>
 <li>Launch the browser and go to
 <b>chrome://extensions</b>; you should
 see the extension listed. </li>
 </ol>
 
+<h2 id="per-extension-install">Using per-extension preference files (Linux only)</h2>
+
+<ol>
+<li>Make the <code>.crx</code> extension file available
+to the machine you want to install the extension on.
+</li>
+<li>Find or create the folder:
+<ul>
+  <li> For a Google Chrome build: <code>/usr/share/google-chrome/extensions</code> </li>
+  <li> For a Chromium build: <code>/usr/share/chromium/extensions</code> </li>
+</ul>
+</li>
+<li>Create a file under this folder with the following name:
+ <code>aaaaaaaaaabbbbbbbbbbcccccccccc.json</code> where the file name (without the extension)
+corresponds to your extension's ID.
+</li>
+<li>In the file created during step 4) above, specify the extension's
+associated <code>.crx</code> complete path along with the
+version your extension:
+<p>
+Example:
+<pre>
+  {
+    "external_crx": "/home/share/extension.crx",
+    "external_version": "1.0"
+  }
+</pre>
+</p>
+</li>
+<li>
+Launch the browser and go to <b>chrome://extensions</b>; you
+should see the extension listed with the proper version number.
+</li>
+</ol>
+
 <h2 id="updating">Updating and uninstalling</h2>
 
 <p>Google Chrome scans the metadata entries
 in the preferences and registry
 each time the browser starts, and makes
 any necessary changes to the installed
 external extensions. </p>
 
 <p>To update your extension to a new version,
 update the file, and then update the version
@@ skipping 53 matching lines @@
   <li>Not specifying the same id/version
     as the one listed in the <code>.crx</code> </li>
   <li>Key created in the wrong location in the registry </li>
   <li>Registry entry points to the wrong path to the <code>.crx</code> file
     (or path specified but no filename) </li>
   <li>Permissions problems on a network share </li>
 </ul>
 
 <br>
 
+<p><b>What are some common mistakes when installing with the per-extension file?</b> </p>
+<ul>
+  <li>Not specifying the same id/version
+    as the one listed in the <code>.crx</code> </li>
+  <li>Extension preference file created in the wrong location or with the wrong extension ID name </li>
+  <li>Extension entry points to the wrong path to the <code>.crx</code> file
+    (or path specified but no filename) </li>
+  <li>Permissions problems on a network share </li>
+  <li>
+    Syntax error in JSON file
+    (forgetting to separate entries with comma or
+    leaving a trailing comma somewhere) </li>
+</ul>
+
+<br>
+
 <p><b>What if the user uninstalls the extension?</b> </p>
 <p>If the user uninstalls the extension through the UI, it will no
 longer be installed or updated on each startup. In other words, the
 external extension is blacklisted. </p>
 
 <br>
 
 <p><b>How do I get off the blacklist?</b> </p>
 <p>If the user uninstalls your extension, you should respect that
 decision. However, if you (the developer) accidentally uninstalled
 your extension through the UI,
 you can remove the blacklist tag
 by installing the extension normally
 through the UI, and then uninstalling it. </p>