[bfcache] Change CHECK to DCHECK in ServiceWorkerVersion

This CL changes CHECK to DCHECK back in ServiceWorkerVersion::
RestoreControlleeFromBackForwardCacheMap, as the fix is verified now.

Bug: 1021718,1034141
Change-Id: I18b3a46e0dade359f34389eabddf6473e2f0775e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994029
Auto-Submit: Yuzu Saijo <yuzus@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730088}

content/browser/service_worker/service_worker_version.cc

@@ -769,11 +769,9 @@ void ServiceWorkerVersion::MoveControlleeToBackForwardCacheMap(
 
 void ServiceWorkerVersion::RestoreControlleeFromBackForwardCacheMap(
     const std::string& client_uuid) {
-  // TODO(crbug.com/1021718): Change these to DCHECK once we figure out the
-  // cause of crash.
-  CHECK(IsBackForwardCacheEnabled());
-  CHECK(!base::Contains(controllee_map_, client_uuid));
-  CHECK(base::Contains(bfcached_controllee_map_, client_uuid));
+  DCHECK(IsBackForwardCacheEnabled());
+  DCHECK(!base::Contains(controllee_map_, client_uuid));
+  DCHECK(base::Contains(bfcached_controllee_map_, client_uuid));
   AddControllee(bfcached_controllee_map_[client_uuid]);
   bfcached_controllee_map_.erase(client_uuid);
 }