content: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

content/public/browser/devtools_agent_host.h

Index: content/public/browser/devtools_agent_host.h
diff --git a/content/public/browser/devtools_agent_host.h b/content/public/browser/devtools_agent_host.h
index fd27ea1fafb21844940f6169d81c4d4c0c6d1a59..419bbd31f089db8714d3f579ba7b98be844dacb4 100644
--- a/content/public/browser/devtools_agent_host.h
+++ b/content/public/browser/devtools_agent_host.h
@@ -12,11 +12,14 @@
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/devtools_agent_host_client.h"
 #include "url/gurl.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace net {
 class ServerSocket;
 }