Move Render(View|Widget)Host and associated classes to content namespace.

content/browser/worker_host/worker_process_host.cc

Index: content/browser/worker_host/worker_process_host.cc
diff --git a/content/browser/worker_host/worker_process_host.cc b/content/browser/worker_host/worker_process_host.cc
index 1d3bd759fe09d20b36f09d5582a75b0e47458cac..6932785672f09fc838f71ab7d04a22a9c1eddab8 100644
--- a/content/browser/worker_host/worker_process_host.cc
+++ b/content/browser/worker_host/worker_process_host.cc
@@ -54,6 +54,7 @@
 using content::BrowserThread;
 using content::ChildProcessData;
 using content::ChildProcessHost;
+using content::RenderViewHostImpl;
 using content::ResourceContext;
 using content::UserMetricsAction;
 using content::WorkerDevToolsManager;