Set current directory when launching Native Messaging processes.

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

 <h1>Native Messaging</h1>
 <p>
 Extensions and apps can exchange messages with native applications using an API
 that is similar to the other <a href="messaging">message passing APIs</a>.
 Native applications that support this feature must register a
 <em>native messaging host</em> that knows how to communicate with the extension.
 Chrome starts the host in a separate process and communicates with it using
 standard input and standard output streams.
 
 <h2 id="native-messaging-host">Native messaging host</h2>
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     </td>
   </tr>
   <tr>
     <td><code>description</code></td>
     <td>Short application description.</td>
   </tr>
   <tr>
     <td><code>path</code></td>
     <td>Path to the native messaging host binary. On Linux and OSX the path must
     be absolute. On Windows it can be relative to the directory in which the
-    manifest file is located.</td>
+    manifest file is located. The host process is started with the current
+    directory set to the directory that contains the host binary. For example if
+    this parameter is set to <code>C:\Application\nm_host.exe</code> then it
+    will be started with current directory <code>C:\Application\</code>.</td>
   </tr>
   <tr>
     <td><code>type</code></td>
     <td>Type of the interface used to communicate with the native messaging
     host. Currently there is only one possible value for this parameter:
     <code>stdio</code>. It indicates that Chrome should use <code>stdin</code>
     and <code>stdout</code> to communicate with the host.</td>
   </tr>
   <tr>
     <td><code>allowed_origins</code></td>
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 and
 <a href="https://developer.chrome.com/extensions/examples/api/nativeMessaging/host.zip">sample host</a>.
 
 Run <code>install_host.bat</code> (Windows) or
 <code>install_host.sh</code> (Linux / OS X) to install the native messaging
 host.
 Then <a href="getstarted#unpacked">load the app</a> and interact with the app.
 Run <code>uninstall_host.bat</code> or <code>uninstall_host.sh</code> to
 unregister the native messaging host when you are done.