Revert of Replace --ppapi-keep-alive-throttle command line switch with IPC parameter.

ppapi/shared_impl/ppapi_constants.h

Index: ppapi/shared_impl/ppapi_constants.h
diff --git a/ppapi/shared_impl/ppapi_constants.h b/ppapi/shared_impl/ppapi_constants.h
deleted file mode 100644
index dcc9b29de5ec06bf8c7009e301e0f13bcde75b9f..0000000000000000000000000000000000000000
--- a/ppapi/shared_impl/ppapi_constants.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2014 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 PPAPI_SHARED_IMPL_PPAPI_CONSTANTS_H_
-#define PPAPI_SHARED_IMPL_PPAPI_CONSTANTS_H_
-
-#include "ppapi/shared_impl/ppapi_shared_export.h"
-
-namespace ppapi {
-
-// Default interval to space out IPC messages sent indicating that a plugin is
-// active and should be kept alive. The value must be smaller than any threshold
-// used to kill inactive plugins by the embedder host.
-const unsigned kKeepaliveThrottleIntervalDefaultMilliseconds = 5000;
-
-}  // namespace ppapi
-
-#endif  // PPAPI_SHARED_IMPL_PPAPI_CONSTANTS_H_