Retain VerifiedRulesetDealer::Handle in the browser process

It is currently not used for verification, it is just held by the
ContentRulesetService and exercised in browser tests.

BUG=637415

Review-Url: https://codereview.chromium.org/2761123004
Cr-Commit-Position: refs/heads/master@{#459849}
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 44c2e7a..2225836 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -1223,7 +1223,8 @@
       user_data_dir.Append(subresource_filter::kTopLevelDirectoryName)
           .Append(subresource_filter::kIndexedRulesetBaseDirectoryName);
   subresource_filter_ruleset_service_ =
-      base::MakeUnique<subresource_filter::ContentRulesetService>();
+      base::MakeUnique<subresource_filter::ContentRulesetService>(
+          blocking_task_runner);
   subresource_filter_ruleset_service_->set_ruleset_service(
       base::MakeUnique<subresource_filter::RulesetService>(
           local_state(), blocking_task_runner,