[ChromeDriver] Add support for attaching multiple DevToolsEventListeners to a DevToolsClient.

chrome/test/chromedriver/chrome_impl.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/test/chromedriver/chrome_impl.h"
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/process_util.h"
@@ skipping 63 matching lines @@
   while (base::Time::Now() < deadline) {
     FetchPagesInfo(context_getter_, port_, &debugger_urls);
     if (debugger_urls.empty())
       base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(100));
     else
       break;
   }
   if (debugger_urls.empty())
     return Status(kUnknownError, "unable to discover open pages");
   client_.reset(new DevToolsClientImpl(
-      socket_factory_, debugger_urls.front(), dom_tracker_.get()));
+      socket_factory_, debugger_urls.front()));
+  client_->AddListener(dom_tracker_.get());
 
   // Perform necessary configuration of the DevTools client.
   // Fetch the root document node so that Inspector will push DOM node
   // information to the client.
   base::DictionaryValue params;
   Status status = client_->SendCommand("DOM.getDocument", params);
   if (status.IsError())
     return status;
   // Enable runtime events to allow tracking execution context creation.
   return client_->SendCommand("Runtime.enable", params);
@@ skipping 197 matching lines @@
   }
   if (status.IsError())
     return status;
 
   if (!cmd_result->GetInteger("nodeId", node_id))
     return Status(kUnknownError, "DOM.requestNode missing int 'nodeId'");
   return Status(kOk);
 }
 
 }  // namespace internal