--- a/dom/media/gmp/ChromiumCDMChild.cpp
+++ b/dom/media/gmp/ChromiumCDMChild.cpp
@@ -1,16 +1,17 @@
 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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 "ChromiumCDMChild.h"
 #include "GMPContentChild.h"
 #include "WidevineUtils.h"
+#include "WidevineFileIO.h"
 #include "WidevineVideoFrame.h"
 #include "GMPLog.h"
 #include "GMPPlatform.h"
 #include "mozilla/Unused.h"
 #include "nsPrintfCString.h"
 #include "base/time.h"
 
 namespace mozilla {
@@ -218,33 +219,37 @@ ChromiumCDMChild::OnLegacySessionError(c
     nsCString(aErrorMessage, aErrorMessageLength));
 }
 
 cdm::FileIO*
 ChromiumCDMChild::CreateFileIO(cdm::FileIOClient * aClient)
 {
   MOZ_ASSERT(IsOnMessageLoopThread());
   GMP_LOG("ChromiumCDMChild::CreateFileIO()");
-  return nullptr;
+  if (!mPersistentStateAllowed) {
+    return nullptr;
+  }
+  return new WidevineFileIO(aClient);
 }
 
 bool
 ChromiumCDMChild::IsOnMessageLoopThread()
 {
   return mPlugin && mPlugin->GMPMessageLoop() == MessageLoop::current();
 }
 
 mozilla::ipc::IPCResult
 ChromiumCDMChild::RecvInit(const bool& aAllowDistinctiveIdentifier,
                            const bool& aAllowPersistentState)
 {
   MOZ_ASSERT(IsOnMessageLoopThread());
   GMP_LOG("ChromiumCDMChild::RecvInit(distinctiveId=%d, persistentState=%d)",
           aAllowDistinctiveIdentifier,
           aAllowPersistentState);
+  mPersistentStateAllowed = aAllowPersistentState;
   if (mCDM) {
     mCDM->Initialize(aAllowDistinctiveIdentifier, aAllowPersistentState);
   }
   return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 ChromiumCDMChild::RecvSetServerCertificate(const uint32_t& aPromiseId,

--- a/dom/media/gmp/ChromiumCDMChild.h
+++ b/dom/media/gmp/ChromiumCDMChild.h
@@ -111,14 +111,15 @@ protected:
 
   GMPContentChild* mPlugin = nullptr;
   cdm::ContentDecryptionModule_8* mCDM = nullptr;
 
   typedef SimpleMap<uint64_t> DurationMap;
   DurationMap mFrameDurations;
 
   bool mDecoderInitialized = false;
+  bool mPersistentStateAllowed = false;
 };
 
 } // namespace gmp
 } // namespace mozilla
 
 #endif // ChromiumCDMChild_h_

--- a/dom/media/gmp/widevine-adapter/moz.build
+++ b/dom/media/gmp/widevine-adapter/moz.build
@@ -11,16 +11,17 @@ SOURCES += [
     'WidevineFileIO.cpp',
     'WidevineUtils.cpp',
     'WidevineVideoDecoder.cpp',
     'WidevineVideoFrame.cpp',
 ]
 
 EXPORTS += [
     'WidevineDecryptor.h',
+    'WidevineFileIO.h',
     'WidevineUtils.h',
     'WidevineVideoFrame.h'
 ]
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/dom/media/gmp',