Add webdriver endpoint to send custom debugger commands

chrome/test/chromedriver/BUILD.gn

 # Copyright 2015 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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 action("embed_js_in_cpp") {
   script = "embed_js_in_cpp.py"
 
@@ skipping 200 matching lines @@
     rebase_path(target_gen_dir, root_build_dir),
   ]
 }
 
 source_set("lib") {
   sources = [
     "//third_party/webdriver/atoms.cc",
     "//third_party/webdriver/atoms.h",
     "alert_commands.cc",
     "alert_commands.h",
+    "base_logger.cc",
+    "base_logger.h",
     "basic_types.cc",
     "basic_types.h",
     "capabilities.cc",
     "capabilities.h",
     "chrome/browser_info.cc",
     "chrome/browser_info.h",
     "chrome_launcher.cc",
     "chrome_launcher.h",
     "command.h",
     "command_listener.h",
     "command_listener_proxy.cc",
     "command_listener_proxy.h",
     "commands.cc",
     "commands.h",
+    "devtools_events_logger.cc",
+    "devtools_events_logger.h",
     "element_commands.cc",
     "element_commands.h",
     "element_util.cc",
     "element_util.h",
     "key_converter.cc",
     "key_converter.h",
     "keycode_text_conversion.h",
     "keycode_text_conversion_mac.mm",
     "keycode_text_conversion_ozone.cc",
     "keycode_text_conversion_win.cc",
@@ skipping 154 matching lines @@
     "//base",
     "//base/test:run_all_unittests",
     "//net",
     "//net:http_server",
     "//net:test_support",
     "//testing/gtest",
     "//ui/events:test_support",
     "//url",
   ]
 }