Allow chromedriver to install an extension and get all installed extension IDs.

chrome/test/pyautolib/pyautolib.i

Index: chrome/test/pyautolib/pyautolib.i
diff --git a/chrome/test/pyautolib/pyautolib.i b/chrome/test/pyautolib/pyautolib.i
index 7bff1bc100d5a1b84f155ce508c273ebe638a90b..d0499b64b904ecdbac2d1c99cee611d41ba502d8 100644
--- a/chrome/test/pyautolib/pyautolib.i
+++ b/chrome/test/pyautolib/pyautolib.i
@@ -379,12 +379,6 @@ class PyUITestBase {
                         int tab_index=0);
 
   // Misc methods
-  %feature("docstring", "Install an extension from the given path.  The path "
-           "must be absolute and may be a crx file or an unpacked extension "
-           "directory. Returns the extension ID if successfully installed and "
-           "loaded. Otherwise, returns the empty string.") InstallExtension;
-  std::string InstallExtension(const std::string& extension_path, bool with_ui);
-
   %feature("docstring", "Get a proxy to the browser window at the given "
                         "zero-based index.") GetBrowserWindow;
   scoped_refptr<BrowserProxy> GetBrowserWindow(int window_index);