service worker: Disable interception when OBJECT/EMBED uses ImageLoader.

Per the specification, service worker should not intercept requests for
OBJECT/EMBED elements.

R=kinuko

Bug: 771933
Change-Id: Ia6da6107dc5c68aa2c2efffde14bd2c51251fbd4
Reviewed-on: https://chromium-review.googlesource.com/927303
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538027}
inline void ImageLoader::EnqueueImageLoadingMicroTask(
    UpdateFromElementBehavior update_behavior,
    ReferrerPolicy referrer_policy) {
  std::unique_ptr<Task> task =
      Task::Create(this, update_behavior, referrer_policy);
  pending_task_ = task->GetWeakPtr();
  Microtask::EnqueueMicrotask(
      WTF::Bind(&Task::Run, WTF::Passed(std::move(task))));
  delay_until_do_update_from_element_ =
      IncrementLoadEventDelayCount::Create(element_->GetDocument());
}

inline void ImageLoader::EnqueueImageLoadingMicroTask(
    UpdateFromElementBehavior update_behavior,
    ReferrerPolicy referrer_policy) {
  std::unique_ptr<Task> task =
      Task::Create(this, update_behavior, referrer_policy);
  pending_task_ = task->GetWeakPtr();
  Microtask::EnqueueMicrotask(
      WTF::Bind(&Task::Run, WTF::Passed(std::move(task))));
  delay_until_do_update_from_element_ =
      IncrementLoadEventDelayCount::Create(element_->GetDocument());
}
