Revert of ServiceWorker: Add CHECK to EmbeddedWorkerRegistry for debug

content/browser/service_worker/embedded_worker_registry.cc

Index: content/browser/service_worker/embedded_worker_registry.cc
diff --git a/content/browser/service_worker/embedded_worker_registry.cc b/content/browser/service_worker/embedded_worker_registry.cc
index 1b75f9407f63cec6135191da510dd9a6c5908fab..51d3c2c5ca2d368f5c1dbb27e3277fdad58fe1cf 100644
--- a/content/browser/service_worker/embedded_worker_registry.cc
+++ b/content/browser/service_worker/embedded_worker_registry.cc
@@ -229,10 +229,6 @@
 
 MessagePortMessageFilter*
 EmbeddedWorkerRegistry::MessagePortMessageFilterForProcess(int process_id) {
-  // TODO(nhiroki): Change this to DCHECK after https://crbug.com/648477 is
-  // fixed.
-  CHECK(
-      base::ContainsKey(process_message_port_message_filter_map_, process_id));
   return process_message_port_message_filter_map_[process_id];
 }