diff --git a/modules/plugin/base/public/nsIPluginStreamInfo.h b/modules/plugin/base/public/nsIPluginStreamInfo.h
new file mode 100644
index 000000000000..fc874022bcea
--- /dev/null
+++ b/modules/plugin/base/public/nsIPluginStreamInfo.h
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+
+#ifndef nsIPluginStreamInfo_h___
+#define nsIPluginStreamInfo_h___
+
+#include "nsplugindefs.h"
+#include "nsISupports.h"
+
+class nsIPluginStreamInfo : public nsISupports {
+public:
+
+	NS_IMETHOD
+	GetContentType(nsMIMEType* result) = 0;
+
+	NS_IMETHOD
+	IsSeekable(PRBool* result) = 0;
+
+	NS_IMETHOD
+	GetLength(PRUint32* result) = 0;
+
+	NS_IMETHOD
+	GetLastModified(PRUint32* result) = 0;
+
+	NS_IMETHOD
+	RequestRead(nsByteRange* rangeList) = 0;
+};
+
+#define NS_IPLUGINSTREAMINFO_IID                 \
+{ /* ed7d4ca0-b005-11d2-adaa-00805f6dec49 */         \
+    0xed7d4ca0,                                      \
+    0xb005,                                          \
+    0x11d2,                                          \
+    {0xad, 0xaa, 0x00, 0x80, 0x5f, 0x6d, 0xec, 0x49} \
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif /* nsIPluginStreamInfo_h___ */
diff --git a/modules/plugin/public/nsIPluginStreamInfo.h b/modules/plugin/public/nsIPluginStreamInfo.h
new file mode 100644
index 000000000000..fc874022bcea
--- /dev/null
+++ b/modules/plugin/public/nsIPluginStreamInfo.h
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+
+#ifndef nsIPluginStreamInfo_h___
+#define nsIPluginStreamInfo_h___
+
+#include "nsplugindefs.h"
+#include "nsISupports.h"
+
+class nsIPluginStreamInfo : public nsISupports {
+public:
+
+	NS_IMETHOD
+	GetContentType(nsMIMEType* result) = 0;
+
+	NS_IMETHOD
+	IsSeekable(PRBool* result) = 0;
+
+	NS_IMETHOD
+	GetLength(PRUint32* result) = 0;
+
+	NS_IMETHOD
+	GetLastModified(PRUint32* result) = 0;
+
+	NS_IMETHOD
+	RequestRead(nsByteRange* rangeList) = 0;
+};
+
+#define NS_IPLUGINSTREAMINFO_IID                 \
+{ /* ed7d4ca0-b005-11d2-adaa-00805f6dec49 */         \
+    0xed7d4ca0,                                      \
+    0xb005,                                          \
+    0x11d2,                                          \
+    {0xad, 0xaa, 0x00, 0x80, 0x5f, 0x6d, 0xec, 0x49} \
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif /* nsIPluginStreamInfo_h___ */