Move code that doesn't depend on PPAPI out of remoting/client/plugin

remoting/client/normalizing_input_filter_mac.h

Index: remoting/client/normalizing_input_filter_mac.h
diff --git a/remoting/client/plugin/normalizing_input_filter_mac.h b/remoting/client/normalizing_input_filter_mac.h
similarity index 89%
rename from remoting/client/plugin/normalizing_input_filter_mac.h
rename to remoting/client/normalizing_input_filter_mac.h
index a262cda8b64e3f738bf03c11cd98357410f30e65..26636ad99d36756738ee27c2b863c8a7b16e3154 100644
--- a/remoting/client/plugin/normalizing_input_filter_mac.h
+++ b/remoting/client/normalizing_input_filter_mac.h
@@ -1,7 +1,10 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifndef REMOTING_CLIENT_NORMALIZING_INPUT_FILTER_MAC_H_
+#define REMOTING_CLIENT_NORMALIZING_INPUT_FILTER_MAC_H_
+
 #include <map>
 
 #include "remoting/protocol/input_filter.h"
@@ -63,3 +66,5 @@ class NormalizingInputFilterMac : public protocol::InputFilter {
 };
 
 }  // namespace remoting
+
+#endif  // REMOTING_CLIENT_NORMALIZING_INPUT_FILTER_MAC_H_