PlzNavigate: Eliminate test_runner bailing out of layout tests too early

components/test_runner/test_runner.cc

Index: components/test_runner/test_runner.cc
diff --git a/components/test_runner/test_runner.cc b/components/test_runner/test_runner.cc
index a410ad41192bcebe663e548c2f35664a0ac67662..e75b5185658c48144582b93fbe12922902b05a0b 100644
--- a/components/test_runner/test_runner.cc
+++ b/components/test_runner/test_runner.cc
@@ -1555,6 +1555,7 @@ TestRunner::TestRunner(TestInterfaces* interfaces)
       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)),
@@ -1586,6 +1587,7 @@ void TestRunner::SetMainView(WebView* 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();
@@ -1837,6 +1839,7 @@ bool TestRunner::IsFramePartOfMainTestWindow(blink::WebFrame* frame) const {
 }
 
 bool TestRunner::tryToSetTopLoadingFrame(WebFrame* frame) {
+  is_navigating_ = false;
   if (!IsFramePartOfMainTestWindow(frame))
     return false;
 
@@ -1850,6 +1853,7 @@ bool TestRunner::tryToSetTopLoadingFrame(WebFrame* frame) {
 }
 
 bool TestRunner::tryToClearTopLoadingFrame(WebFrame* frame) {
+  is_navigating_ = false;
   if (!IsFramePartOfMainTestWindow(frame))
     return false;
 
@@ -2735,8 +2739,9 @@ void TestRunner::CheckResponseMimeType() {
 
 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();
 }