[ChromeDriver] Detect page loading status when the page is not loaded at all.

chrome/test/chromedriver/chrome/navigation_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/chrome/navigation_tracker.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "chrome/test/chromedriver/chrome/devtools_client.h"
 #include "chrome/test/chromedriver/chrome/status.h"
@@ skipping 14 matching lines @@
       loading_state_(known_state),
       browser_info_(browser_info) {
   client_->AddListener(this);
 }
 
 NavigationTracker::~NavigationTracker() {}
 
 Status NavigationTracker::IsPendingNavigation(const std::string& frame_id,
                                               bool* is_pending) {
   if (loading_state_ == kUnknown) {
+    scoped_ptr<base::DictionaryValue> result;
+
+    // In the case that a http request is sent to server to fetch the page
+    // content and the server hasn't responded at all, a dummy page is created
+    // for the new window. In such case, the baseURL will be empty.
+    base::DictionaryValue empty_params;
+    Status status = client_->SendCommandAndGetResult(
+        "DOM.getDocument", empty_params, &result);
+    std::string base_url;
+    if (status.IsError() || !result->GetString("root.baseURL", &base_url))
+      return Status(kUnknownError, "cannot determine loading status", status);
+    if (base_url.empty()) {
+      *is_pending = true;
+      loading_state_ = kLoading;
+      return Status(kOk);
+    }
+
     // If the loading state is unknown (which happens after first connecting),
     // force loading to start and set the state to loading. This will
     // cause a frame start event to be received, and the frame stop event
     // will not be received until all frames are loaded.
     // Loading is forced to start by attaching a temporary iframe.
     // Forcing loading to start is not necessary if the main frame is not yet
     // loaded.
     const char kStartLoadingIfMainFrameNotLoading[] =
        "var isLoaded = document.readyState == 'complete' ||"
        "    document.readyState == 'interactive';"
        "if (isLoaded) {"
        "  var frame = document.createElement('iframe');"
        "  frame.src = 'about:blank';"
        "  document.body.appendChild(frame);"
        "  window.setTimeout(function() {"
        "    document.body.removeChild(frame);"
        "  }, 0);"
        "}";
     base::DictionaryValue params;
     params.SetString("expression", kStartLoadingIfMainFrameNotLoading);
-    scoped_ptr<base::DictionaryValue> result;
-    Status status = client_->SendCommandAndGetResult(
+    status = client_->SendCommandAndGetResult(
         "Runtime.evaluate", params, &result);
     if (status.IsError())
       return Status(kUnknownError, "cannot determine loading status", status);
 
     // Between the time the JavaScript is evaluated and SendCommandAndGetResult
     // returns, OnEvent may have received info about the loading state.
     // This is only possible during a nested command. Only set the loading state
     // if the loading state is still unknown.
     if (loading_state_ == kUnknown)
       loading_state_ = kLoading;
   }
   *is_pending = loading_state_ == kLoading;
-  if (frame_id.empty())
+  if (frame_id.empty()) {
     *is_pending |= scheduled_frame_set_.size() > 0;
-  else
+    *is_pending |= pending_frame_set_.size() > 0;
+  } else {
     *is_pending |= scheduled_frame_set_.count(frame_id) > 0;
+    *is_pending |= pending_frame_set_.count(frame_id) > 0;
+  }
   return Status(kOk);
 }
 
 Status NavigationTracker::OnConnected(DevToolsClient* client) {
   ResetLoadingState(kUnknown);
 
   // Enable page domain notifications to allow tracking navigation state.
   base::DictionaryValue empty_params;
   return client_->SendCommand("Page.enable", empty_params);
 }
@@ skipping 118 matching lines @@
       loading_state_ = kLoading;
   }
   return Status(kOk);
 }
 
 void NavigationTracker::ResetLoadingState(LoadingState loading_state) {
   loading_state_ = loading_state;
   pending_frame_set_.clear();
   scheduled_frame_set_.clear();
 }