[ChromeDriver] Subscribe PerformanceLogger to CommandListener interface

chrome/test/chromedriver/util.h

 // Copyright (c) 2013 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_CHROMEDRIVER_UTIL_H_
 #define CHROME_TEST_CHROMEDRIVER_UTIL_H_
 
 #include <string>
 
 namespace base {
 class FilePath;
 class ListValue;
 }
 
+struct Session;
 class Status;
 class WebView;
 
 // Generates a random, 32-character hexidecimal ID.
 std::string GenerateId();
 
 // Send a sequence of key strokes to the active Element in window.
 Status SendKeysOnWindow(
     WebView* web_view,
     const base::ListValue* key_list,
     bool release_modifiers,
     int* sticky_modifiers);
 
 // Decodes the given base64-encoded string, after removing any newlines,
 // which are required in some base64 standards. Returns true on success.
 bool Base64Decode(const std::string& base64, std::string* bytes);
 
 // Unzips the sole file contained in the given zip data |bytes| into
 // |unzip_dir|. The zip data may be a normal zip archive or a single zip file
 // entry. If the unzip successfully produced one file, returns true and sets
 // |file| to the unzipped file.
 // TODO(kkania): Remove the ability to parse single zip file entries when
 // the current versions of all WebDriver clients send actual zip files.
 Status UnzipSoleFile(const base::FilePath& unzip_dir,
                      const std::string& bytes,
                      base::FilePath* file);
 
+// Calls BeforeCommand for each of |session|'s |CommandListener|s.
+void NotifySessionListenersBeforeCommand(Session* session,
+                                         const std::string& command_name);
+
 #endif  // CHROME_TEST_CHROMEDRIVER_UTIL_H_