Define DevTools content API

content/browser/debugger/worker_devtools_message_filter.cc

Index: content/browser/debugger/worker_devtools_message_filter.cc
diff --git a/content/browser/debugger/worker_devtools_message_filter.cc b/content/browser/debugger/worker_devtools_message_filter.cc
index 3d1795fd3a29ca061d537ec6d105ea4e4a091872..537f136336cd5cbfad970b076815f48b9a1da11b 100644
--- a/content/browser/debugger/worker_devtools_message_filter.cc
+++ b/content/browser/debugger/worker_devtools_message_filter.cc
@@ -9,6 +9,8 @@
 #include "content/common/devtools_messages.h"
 #include "content/common/worker_messages.h"
 
+namespace content {
+
 WorkerDevToolsMessageFilter::WorkerDevToolsMessageFilter(
     int worker_process_host_id)
     : worker_process_host_id_(worker_process_host_id),
@@ -44,3 +46,5 @@ void WorkerDevToolsMessageFilter::OnSaveAgentRumtimeState(
   WorkerDevToolsManager::GetInstance()->SaveAgentRuntimeState(
       worker_process_host_id_, current_routing_id_, state);
 }
+
+}  // namespace content