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

chrome/test/pyautolib/pyautolib.h

Index: chrome/test/pyautolib/pyautolib.h
diff --git a/chrome/test/pyautolib/pyautolib.h b/chrome/test/pyautolib/pyautolib.h
index d08a8ba20596e15f0a09dd95a7d5c986811a4402..f1ca48d94fb92cae9eb329df90a2209f026d770e 100644
--- a/chrome/test/pyautolib/pyautolib.h
+++ b/chrome/test/pyautolib/pyautolib.h
@@ -130,11 +130,6 @@ class PyUITestBase : public UITestBase {
   // Fetch the number of browser windows. Includes popups.
   int GetBrowserWindowCount();
 
-  // Installs the extension.  Returns the extension ID only if the extension
-  // was installed and loaded successfully.  Otherwise, returns the empty
-  // string.  Overinstalls will fail.
-  std::string InstallExtension(const std::string& extension_path, bool with_ui);
-
   // Returns bookmark bar visibility state.
   bool GetBookmarkBarVisibility();