Add missing vertical line in comment.

Change-Id: Ib4f3e3224d88c970b96f21e898f60fc3099ab4bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2362904Reviewed-by: Carlos Knippschild <carlosk@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799744}

components/offline_pages/core/prefetch/prefetch_gcm_app_handler.h

@@ -44,7 +44,7 @@ class PrefetchGCMAppHandler : public gcm::GCMAppHandler,
   std::string GetAppId() const override;
 
  private:
-  // Not owned, PrefetchService owns |this.
+  // Not owned, PrefetchService owns |this|.
   PrefetchService* prefetch_service_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(PrefetchGCMAppHandler);