Force-generate a frame before the end of a layout test.

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 2334 matching lines @@
 void TestRunner::SetPluginsEnabled(bool enabled) {
   delegate_->Preferences()->plugins_enabled = enabled;
   delegate_->ApplyPreferences();
 }
 
 bool TestRunner::GetAnimationScheduled() const {
   bool is_animation_scheduled = !widgets_with_scheduled_animations_.empty();
   return is_animation_scheduled;
 }
 
+void TestRunner::RunPendingAnimations()
+{
+  for (auto& widget: widgets_with_scheduled_animations_) {
+    widget->updateAllLifecyclePhases();
+  }
+  widgets_with_scheduled_animations_.clear();
+}
+
 void TestRunner::OnAnimationScheduled(blink::WebWidget* widget) {
   widgets_with_scheduled_animations_.insert(widget);
 }
 
 void TestRunner::OnAnimationBegun(blink::WebWidget* widget) {
   widgets_with_scheduled_animations_.erase(widget);
 }
 
 void TestRunner::DumpEditingCallbacks() {
   layout_test_runtime_flags_.set_dump_editting_callbacks(true);
@@ skipping 361 matching lines @@
 
 void TestRunner::NotifyDone() {
   if (layout_test_runtime_flags_.wait_until_done() && !topLoadingFrame() &&
       !will_navigate_ && work_queue_.is_empty())
     delegate_->TestFinished();
   layout_test_runtime_flags_.set_wait_until_done(false);
   OnLayoutTestRuntimeFlagsChanged();
 }
 
 }  // namespace test_runner