DocumentLoader: unpause virtual time when destroying body loader

Virtual time should only be paused while body loader is active.

Bug: none
Change-Id: I479bc7e85c7dd30dfaf5fc8f61c5be6cd6859288
Reviewed-on: https://chromium-review.googlesource.com/c/1483215
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634810}

third_party/blink/renderer/core/loader/document_loader.cc

@@ -951,6 +951,7 @@ void DocumentLoader::ProcessDataBuffer() {
 void DocumentLoader::StopLoading() {
   fetcher_->StopFetching();
   body_loader_.reset();
+  virtual_time_pauser_.UnpauseVirtualTime();
   if (!SentDidFinishLoad())
     LoadFailed(ResourceError::CancelledError(Url()));
 }