PlzNavigate: Eliminate test_runner bailing out of layout tests too early

components/test_runner/test_runner.cc

 // Copyright 2014 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 "components/test_runner/test_runner.h"
 
 #include <stddef.h>
 #include <limits>
 #include <utility>
 
@@ skipping 1537 matching lines @@
 TestRunner::TestRunner(TestInterfaces* interfaces)
     : test_is_running_(false),
       close_remaining_windows_(false),
       work_queue_(this),
       web_history_item_count_(0),
       test_interfaces_(interfaces),
       delegate_(nullptr),
       main_view_(nullptr),
       mock_content_settings_client_(
           new MockContentSettingsClient(&layout_test_runtime_flags_)),
+      is_navigating_(false),
       credential_manager_client_(new MockCredentialManagerClient),
       mock_screen_orientation_client_(new MockScreenOrientationClient),
       spellcheck_(new SpellCheckClient(this)),
       chooser_count_(0),
       previously_focused_view_(nullptr),
       is_web_platform_tests_mode_(false),
       weak_factory_(this) {}
 
 TestRunner::~TestRunner() {}
 
@@ skipping 11 matching lines @@
   if (speech_recognizer_)
     speech_recognizer_->SetDelegate(delegate);
 }
 
 void TestRunner::SetMainView(WebView* web_view) {
   main_view_ = web_view;
 }
 
 void TestRunner::Reset() {
   is_web_platform_tests_mode_ = false;
+  is_navigating_ = false;
   top_loading_frame_ = nullptr;
   layout_test_runtime_flags_.Reset();
   mock_screen_orientation_client_->ResetData();
   drag_image_.reset();
   widgets_with_scheduled_animations_.clear();
 
   WebSecurityPolicy::resetOriginAccessWhitelists();
 #if defined(__linux__) || defined(ANDROID)
   WebFontRendering::setSubpixelPositioning(false);
 #endif
@@ skipping 231 matching lines @@
 
 const std::set<std::string>* TestRunner::httpHeadersToClear() const {
   return &http_headers_to_clear_;
 }
 
 bool TestRunner::IsFramePartOfMainTestWindow(blink::WebFrame* frame) const {
   return test_is_running_ && frame->top()->view() == main_view_;
 }
 
 bool TestRunner::tryToSetTopLoadingFrame(WebFrame* frame) {
+  is_navigating_ = false;

[clamy, 2016/07/19 13:50:34]

Can it be possible for the new frame to be navigating at this point?

[blundell, 2016/07/21 10:02:18]

Yes. The flow is this:

- FrameLoader::startLoad() is invoked. This results in a browser-side navigation
and causes WebFrameClient::didStartLoading() to be invoked, so TestRunner's
|is_navigating_| is true.
- The browser-side navigation sends back an IPC that causes
RenderFrameImpl::OnCommitNavigation() to be invoked.
- That method calls into WebLocalFrame::load(), which causes
FrameLoader::startLoad() to be invoked again. This time it goes through to the
end instead of short-circuiting out early and causes
WebFrameClient::didStartProvisionalLoad() to be invoked, which in turn invokes
TestRunner::tryToSetTopLoadingFrame().

   if (!IsFramePartOfMainTestWindow(frame))
     return false;
 
   if (top_loading_frame_ || layout_test_runtime_flags_.have_top_loading_frame())
     return false;
 
   top_loading_frame_ = frame;
   layout_test_runtime_flags_.set_have_top_loading_frame(true);
   OnLayoutTestRuntimeFlagsChanged();
   return true;
 }
 
 bool TestRunner::tryToClearTopLoadingFrame(WebFrame* frame) {
+  is_navigating_ = false;
   if (!IsFramePartOfMainTestWindow(frame))
     return false;
 
   if (frame != top_loading_frame_)
     return false;
 
   top_loading_frame_ = nullptr;
   DCHECK(layout_test_runtime_flags_.have_top_loading_frame());
   layout_test_runtime_flags_.set_have_top_loading_frame(false);
   OnLayoutTestRuntimeFlagsChanged();
@@ skipping 865 matching lines @@
   if (mimeType != "text/plain")
     return;
 
   layout_test_runtime_flags_.set_dump_as_text(true);
   layout_test_runtime_flags_.set_generate_pixel_results(false);
   OnLayoutTestRuntimeFlagsChanged();
 }
 
 void TestRunner::NotifyDone() {
   if (layout_test_runtime_flags_.wait_until_done() && !topLoadingFrame() &&
-      work_queue_.is_empty())
+      !is_navigating_ && work_queue_.is_empty()) {
     delegate_->TestFinished();
+  }
   layout_test_runtime_flags_.set_wait_until_done(false);
   OnLayoutTestRuntimeFlagsChanged();
 }
 
 }  // namespace test_runner