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

chrome/test/webdriver/webdriver_session.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_TEST_WEBDRIVER_WEBDRIVER_SESSION_H_
 #define CHROME_TEST_WEBDRIVER_WEBDRIVER_SESSION_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 289 matching lines @@
 
   // Gets the attribute of the given element. If there are no errors, the
   // function sets |value| and the caller takes ownership.
   Error* GetAttribute(const ElementId& element, const std::string& key,
                       base::Value** value);
 
   // Waits for all tabs to stop loading. Returns true on success.
   Error* WaitForAllTabsToStopLoading();
 
   // Install packed extension at |path|.
-  Error* InstallExtension(const FilePath& path);
+  Error* InstallExtensionDeprecated(const FilePath& path);
+
+  // Get installed extensions IDs.
+  Error* GetInstalledExtensions(std::vector<std::string>* extension_ids);
+
+  // Install extension at |path|.
+  Error* InstallExtension(const FilePath& path, std::string* extension_id);
 
   const std::string& id() const;
 
   const FrameId& current_target() const;
 
   void set_async_script_timeout(int timeout_ms);
   int async_script_timeout() const;
 
   void set_implicit_wait(int timeout_ms);
   int implicit_wait() const;
@@ skipping 84 matching lines @@
   Options options_;
 
   DISALLOW_COPY_AND_ASSIGN(Session);
 };
 
 }  // namespace webdriver
 
 DISABLE_RUNNABLE_METHOD_REFCOUNT(webdriver::Session);
 
 #endif  // CHROME_TEST_WEBDRIVER_WEBDRIVER_SESSION_H_