--- a/dom/cache/CacheStreamControlChild.cpp
+++ b/dom/cache/CacheStreamControlChild.cpp
@@ -15,20 +15,20 @@
 #include "mozilla/ipc/PBackgroundChild.h"
 #include "mozilla/ipc/PFileDescriptorSetChild.h"
 #include "nsISupportsImpl.h"
 
 namespace mozilla {
 namespace dom {
 namespace cache {
 
+using mozilla::dom::OptionalFileDescriptorSet;
 using mozilla::ipc::AutoIPCStream;
 using mozilla::ipc::FileDescriptor;
 using mozilla::ipc::FileDescriptorSetChild;
-using mozilla::ipc::OptionalFileDescriptorSet;
 using mozilla::ipc::PFileDescriptorSetChild;
 
 // declared in ActorUtils.h
 PCacheStreamControlChild*
 AllocPCacheStreamControlChild()
 {
   return new CacheStreamControlChild();
 }

--- a/dom/cache/CacheStreamControlParent.cpp
+++ b/dom/cache/CacheStreamControlParent.cpp
@@ -15,19 +15,19 @@
 #include "mozilla/ipc/PBackgroundParent.h"
 #include "mozilla/ipc/PFileDescriptorSetParent.h"
 #include "nsISupportsImpl.h"
 
 namespace mozilla {
 namespace dom {
 namespace cache {
 
+using mozilla::dom::OptionalFileDescriptorSet;
 using mozilla::ipc::FileDescriptor;
 using mozilla::ipc::FileDescriptorSetParent;
-using mozilla::ipc::OptionalFileDescriptorSet;
 using mozilla::ipc::PFileDescriptorSetParent;
 
 // declared in ActorUtils.h
 void
 DeallocPCacheStreamControlParent(PCacheStreamControlParent* aActor)
 {
   delete aActor;
 }

--- a/dom/indexedDB/PBackgroundIDBSharedTypes.ipdlh
+++ b/dom/indexedDB/PBackgroundIDBSharedTypes.ipdlh
@@ -2,16 +2,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBackgroundIDBDatabaseFile;
 include protocol PBackgroundMutableFile;
 include protocol PBlob;
 
 include DOMTypes;
+include ProtocolTypes;
 
 include "mozilla/dom/indexedDB/SerializationHelpers.h";
 include "mozilla/dom/quota/SerializationHelpers.h";
 
 using struct mozilla::null_t
   from "ipc/IPCMessageUtils.h";
 
 using struct mozilla::void_t

--- a/dom/ipc/Blob.cpp
+++ b/dom/ipc/Blob.cpp
@@ -561,17 +561,17 @@ private:
   Recv__delete__(const InputStreamParams& aParams,
                  const OptionalFileDescriptorSet& aFDs) override;
 };
 
 class InputStreamParent final
   : public PBlobStreamParent
 {
   typedef mozilla::ipc::InputStreamParams InputStreamParams;
-  typedef mozilla::ipc::OptionalFileDescriptorSet OptionalFileDescriptorSet;
+  typedef mozilla::dom::OptionalFileDescriptorSet OptionalFileDescriptorSet;
 
   bool* mSyncLoopGuard;
   InputStreamParams* mParams;
   OptionalFileDescriptorSet* mFDs;
 
 #ifdef DEBUG
   PRThread* mOwningThread;
 #endif

new file mode 100644
--- /dev/null
+++ b/dom/ipc/BlobTypes.ipdlh
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+include protocol PFileDescriptorSet;
+
+using struct mozilla::void_t
+  from "ipc/IPCMessageUtils.h";
+
+namespace mozilla {
+namespace dom {
+
+union OptionalFileDescriptorSet
+{
+  PFileDescriptorSet;
+  FileDescriptor[];
+  void_t;
+};
+
+}
+}

--- a/dom/ipc/DOMTypes.ipdlh
+++ b/dom/ipc/DOMTypes.ipdlh
@@ -1,25 +1,23 @@
 /* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 8 -*- */
 /* vim: set sw=4 ts=8 et tw=80 ft=cpp : */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBlob;
+include ProtocolTypes;
 
 using struct mozilla::void_t
   from "ipc/IPCMessageUtils.h";
 
 using struct mozilla::SerializedStructuredCloneBuffer
   from "ipc/IPCMessageUtils.h";
 
-using struct nsID
-  from "nsID.h";
-
 namespace mozilla {
 namespace dom {
 
 union OptionalID
 {
   nsID;
   void_t;
 };

--- a/dom/ipc/PBlob.ipdl
+++ b/dom/ipc/PBlob.ipdl
@@ -3,16 +3,17 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBackground;
 include protocol PBlobStream;
 include protocol PContent;
 include protocol PContentBridge;
 include protocol PFileDescriptorSet;
 
+include BlobTypes;
 include DOMTypes;
 include InputStreamParams;
 
 namespace mozilla {
 namespace dom {
 
 union ResolveMysteryParams
 {

--- a/dom/ipc/PBlobStream.ipdl
+++ b/dom/ipc/PBlobStream.ipdl
@@ -1,14 +1,15 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBlob;
 include protocol PFileDescriptorSet;
+include BlobTypes;
 include InputStreamParams;
 
 namespace mozilla {
 namespace dom {
 
 protocol PBlobStream
 {
   manager PBlob;

--- a/dom/ipc/moz.build
+++ b/dom/ipc/moz.build
@@ -85,16 +85,17 @@ UNIFIED_SOURCES += [
 SOURCES += [
     'Blob.cpp',
     'ContentChild.cpp',
     'CrashReporterChild.cpp',
     'ProcessHangMonitor.cpp',
 ]
 
 IPDL_SOURCES += [
+    'BlobTypes.ipdlh',
     'DOMTypes.ipdlh',
     'PBlob.ipdl',
     'PBlobStream.ipdl',
     'PBrowser.ipdl',
     'PBrowserOrId.ipdlh',
     'PColorPicker.ipdl',
     'PContent.ipdl',
     'PContentBridge.ipdl',

--- a/ipc/glue/IPCStream.ipdlh
+++ b/ipc/glue/IPCStream.ipdlh
@@ -1,13 +1,14 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PSendStream;
+include BlobTypes;
 include InputStreamParams;
 
 namespace mozilla {
 namespace ipc {
 
 // Do not use this directly.  See IPCStream below.
 struct InputStreamParamsWithFds
 {

--- a/ipc/glue/InputStreamParams.ipdlh
+++ b/ipc/glue/InputStreamParams.ipdlh
@@ -1,16 +1,14 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBlob;
-include protocol PFileDescriptorSet;
-
-include DOMTypes;
+include ProtocolTypes;
 
 using struct mozilla::void_t
   from "ipc/IPCMessageUtils.h";
 
 namespace mozilla {
 namespace ipc {
 
 struct StringInputStreamParams
@@ -81,17 +79,10 @@ struct MIMEInputStreamParams
 {
   OptionalInputStreamParams optionalStream;
   nsCString headers;
   nsCString contentLength;
   bool startedReading;
   bool addContentLength;
 };
 
-union OptionalFileDescriptorSet
-{
-  PFileDescriptorSet;
-  FileDescriptor[];
-  void_t;
-};
-
 } // namespace ipc
 } // namespace mozilla

--- a/ipc/glue/PBackground.ipdl
+++ b/ipc/glue/PBackground.ipdl
@@ -23,16 +23,17 @@ include protocol PSendStream;
 include protocol PServiceWorkerManager;
 include protocol PUDPSocket;
 include protocol PVsync;
 
 include DOMTypes;
 include PBackgroundSharedTypes;
 include PBackgroundIDBSharedTypes;
 include PFileSystemParams;
+include ProtocolTypes;
 
 include "mozilla/dom/cache/IPCUtils.h";
 
 using mozilla::dom::cache::Namespace
   from "mozilla/dom/cache/Types.h";
 
 using mozilla::dom::asmjscache::OpenMode
   from "mozilla/dom/asmjscache/AsmJSCache.h";

--- a/ipc/glue/ProtocolTypes.ipdlh
+++ b/ipc/glue/ProtocolTypes.ipdlh
@@ -1,14 +1,17 @@
 /* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 8 -*- */
 /* vim: set sw=4 ts=8 et tw=80 ft=cpp : */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+using struct nsID
+  from "nsID.h";
+
 namespace mozilla {
 namespace ipc {
 
 struct ProtocolFdMapping
 {
     uint32_t protocolId;
     FileDescriptor fd;
 };

--- a/netwerk/ipc/NeckoChannelParams.ipdlh
+++ b/netwerk/ipc/NeckoChannelParams.ipdlh
@@ -3,16 +3,17 @@
 
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PHttpChannel;
 include protocol PFTPChannel;
 include protocol PRtspChannel;
+include BlobTypes;
 include URIParams;
 include InputStreamParams;
 include PBackgroundSharedTypes;
 
 using mozilla::NeckoOriginAttributes from "mozilla/ipc/BackgroundUtils.h";
 using struct mozilla::void_t from "ipc/IPCMessageUtils.h";
 using RequestHeaderTuples from "mozilla/net/PHttpChannelParams.h";
 using struct nsHttpAtom from "nsHttp.h";