[ChromeDriver] Remove FrameTracker's dependency on DomTracker.

chrome/test/chromedriver/frame_tracker.cc

 // 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.
 
 #include "chrome/test/chromedriver/frame_tracker.h"
 
 #include <utility>
 
 #include "base/json/json_writer.h"
 #include "base/logging.h"
@@ skipping 20 matching lines @@
     const std::string& frame_id, int* context_id) {
   if (frame_to_context_map_.count(frame_id) == 0)
     return Status(kUnknownError, "frame does not have execution context");
   *context_id = frame_to_context_map_[frame_id];
   return Status(kOk);
 }
 
 Status FrameTracker::OnConnected() {
   // Enable runtime events to allow tracking execution context creation.
   base::DictionaryValue params;
-  return client_->SendCommand("Runtime.enable", params);
+  Status status = client_->SendCommand("Runtime.enable", params);
+  if (status.IsError())
+    return status;
+  return client_->SendCommand("DOM.getDocument", params);
 }
 
 void FrameTracker::OnEvent(const std::string& method,
                            const base::DictionaryValue& params) {
   if (method == "Runtime.executionContextCreated") {
     const base::DictionaryValue* context;
     if (!params.GetDictionary("context", &context)) {
       LOG(ERROR) << "Runtime.executionContextCreated missing dict 'context'";
       return;
     }
     int context_id;
     std::string frame_id;
     if (!context->GetInteger("id", &context_id) ||
         !context->GetString("frameId", &frame_id)) {
       std::string json;
       base::JSONWriter::Write(context, &json);
       LOG(ERROR) << "Runtime.executionContextCreated has invalid 'context': "
                  << json;
       return;
     }
     frame_to_context_map_.insert(std::make_pair(frame_id, context_id));
     context_to_frame_map_.insert(std::make_pair(context_id, frame_id));
   } else if (method == "DOM.documentUpdated") {
     frame_to_context_map_.clear();
     context_to_frame_map_.clear();
   }
 }