--- a/gfx/2d/DrawEventRecorder.cpp
+++ b/gfx/2d/DrawEventRecorder.cpp
@@ -31,18 +31,17 @@ DrawEventRecorderPrivate::RecordEvent(co
   WriteElement(*mOutputStream, aEvent.mType);
 
   aEvent.RecordToStream(*mOutputStream);
 
   Flush();
 }
 
 DrawEventRecorderFile::DrawEventRecorderFile(const char *aFilename)
-  : DrawEventRecorderPrivate(nullptr)
-  , mOutputFilename(aFilename)
+  : DrawEventRecorderPrivate(nullptr) 
   , mOutputFile(aFilename, ofstream::binary)
 {
   mOutputStream = &mOutputFile;
 
   WriteHeader();
 }
 
 DrawEventRecorderFile::~DrawEventRecorderFile()
@@ -51,35 +50,16 @@ DrawEventRecorderFile::~DrawEventRecorde
 }
 
 void
 DrawEventRecorderFile::Flush()
 {
   mOutputFile.flush();
 }
 
-void
-DrawEventRecorderFile::OpenAndTruncate()
-{
-  if (mOutputFile.is_open()) {
-    return;
-  }
-
-  mOutputFile.open(mOutputFilename.c_str(), ofstream::binary | ofstream::trunc);
-  WriteHeader();
-}
-
-void
-DrawEventRecorderFile::Close()
-{
-  MOZ_ASSERT(mOutputFile.is_open());
-
-  mOutputFile.close();
-}
-
 DrawEventRecorderMemory::DrawEventRecorderMemory()
   : DrawEventRecorderPrivate(nullptr)
 {
   mOutputStream = &mMemoryStream;
 
   WriteHeader();
 }
 

--- a/gfx/2d/DrawEventRecorder.h
+++ b/gfx/2d/DrawEventRecorder.h
@@ -5,17 +5,16 @@
 
 #ifndef MOZILLA_GFX_DRAWEVENTRECORDER_H_
 #define MOZILLA_GFX_DRAWEVENTRECORDER_H_
 
 #include "2D.h"
 #include "RecordedEvent.h"
 #include <ostream>
 #include <fstream>
-#include <string>
 
 #if defined(_MSC_VER)
 #include <unordered_set>
 #else
 #include <set>
 #endif
 
 namespace mozilla {
@@ -74,34 +73,19 @@ protected:
 
 class DrawEventRecorderFile : public DrawEventRecorderPrivate
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DrawEventRecorderFile)
   explicit DrawEventRecorderFile(const char *aFilename);
   ~DrawEventRecorderFile();
 
-  /**
-   * Re-opens and truncates the file. The recorder does NOT forget which objects
-   * it has recorded. This can be used with Close, so that a recording can be
-   * processed in chunks. If the file is already open this does nothing.
-   */
-  void OpenAndTruncate();
-
-  /**
-   * Closes the file so that it can be processed. The recorder does NOT forget
-   * which objects it has recorded. This can be used with OpenAndTruncate, so
-   * that a recording can be processed in chunks. The file must be open.
-   */
-  void Close();
-
 private:
   virtual void Flush();
 
-  std::string mOutputFilename;
   std::ofstream mOutputFile;
 };
 
 class DrawEventRecorderMemory final : public DrawEventRecorderPrivate
 {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DrawEventRecorderMemory)
 

--- a/layout/printing/ipc/PRemotePrintJob.ipdl
+++ b/layout/printing/ipc/PRemotePrintJob.ipdl
@@ -19,17 +19,18 @@ both:
 
 parent:
   // Initialize the real print device with the given information.
   async InitializePrint(nsString aDocumentTitle, nsString aPrintToFile,
                         int32_t aStartPage, int32_t aEndPage);
 
   // Translate the stored page recording and play back the events to the real
   // print device.
-  async ProcessPage(nsCString aPageFileName);
+  // This will always deallocate the shared memory.
+  async ProcessPage(Shmem aStoredPage);
 
   // This informs the real print device that we've finished, so it can trigger
   // the actual print.
   async FinalizePrint();
 
   // Report a state change to listeners in the parent process.
   async StateChange(long aStateFlags,
                     nsresult aStatus);

--- a/layout/printing/ipc/RemotePrintJobChild.cpp
+++ b/layout/printing/ipc/RemotePrintJobChild.cpp
@@ -42,22 +42,22 @@ bool
 RemotePrintJobChild::RecvPrintInitializationResult(const nsresult& aRv)
 {
   mPrintInitialized = true;
   mInitializationResult = aRv;
   return true;
 }
 
 void
-RemotePrintJobChild::ProcessPage(const nsCString& aPageFileName)
+RemotePrintJobChild::ProcessPage(Shmem& aStoredPage)
 {
   MOZ_ASSERT(mPagePrintTimer);
 
   mPagePrintTimer->WaitForRemotePrint();
-  Unused << SendProcessPage(aPageFileName);
+  Unused << SendProcessPage(aStoredPage);
 }
 
 bool
 RemotePrintJobChild::RecvPageProcessed()
 {
   MOZ_ASSERT(mPagePrintTimer);
 
   mPagePrintTimer->RemotePrintFinished();

--- a/layout/printing/ipc/RemotePrintJobChild.h
+++ b/layout/printing/ipc/RemotePrintJobChild.h
@@ -31,17 +31,17 @@ public:
 
   nsresult InitializePrint(const nsString& aDocumentTitle,
                            const nsString& aPrintToFile,
                            const int32_t& aStartPage,
                            const int32_t& aEndPage);
 
   bool RecvPrintInitializationResult(const nsresult& aRv) final;
 
-  void ProcessPage(const nsCString& aPageFileName);
+  void ProcessPage(Shmem& aStoredPage);
 
   bool RecvPageProcessed() final;
 
   bool RecvAbortPrint(const nsresult& aRv) final;
 
   void SetPagePrintTimer(nsPagePrintTimer* aPagePrintTimer);
 
   void SetPrintEngine(nsPrintEngine* aPrintEngine);

--- a/layout/printing/ipc/RemotePrintJobParent.cpp
+++ b/layout/printing/ipc/RemotePrintJobParent.cpp
@@ -1,24 +1,22 @@
 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* 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 "RemotePrintJobParent.h"
 
-#include <fstream>
+#include <istream>
 
 #include "gfxContext.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Unused.h"
-#include "nsAppDirectoryServiceDefs.h"
 #include "nsComponentManagerUtils.h"
-#include "nsDirectoryServiceUtils.h"
 #include "nsDeviceContext.h"
 #include "nsIDeviceContextSpec.h"
 #include "nsIPrintSettings.h"
 #include "nsIWebProgressListener.h"
 #include "PrintTranslator.h"
 
 namespace mozilla {
 namespace layout {
@@ -78,73 +76,56 @@ RemotePrintJobParent::InitializePrintDev
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
   return NS_OK;
 }
 
 bool
-RemotePrintJobParent::RecvProcessPage(const nsCString& aPageFileName)
+RemotePrintJobParent::RecvProcessPage(Shmem&& aStoredPage)
 {
-  nsresult rv = PrintPage(aPageFileName);
+  nsresult rv = PrintPage(aStoredPage);
+
+  // Always deallocate the shared memory no matter what the result.
+  if (!DeallocShmem(aStoredPage)) {
+    NS_WARNING("Failed to deallocated shared memory, remote print will abort.");
+    rv = NS_ERROR_FAILURE;
+  }
 
   if (NS_FAILED(rv)) {
     Unused << SendAbortPrint(rv);
   } else {
     Unused << SendPageProcessed();
   }
 
   return true;
 }
 
 nsresult
-RemotePrintJobParent::PrintPage(const nsCString& aPageFileName)
+RemotePrintJobParent::PrintPage(const Shmem& aStoredPage)
 {
   MOZ_ASSERT(mPrintDeviceContext);
 
   nsresult rv = mPrintDeviceContext->BeginPage();
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
-  nsCOMPtr<nsIFile> recordingFile;
-  rv = NS_GetSpecialDirectory(NS_APP_CONTENT_PROCESS_TEMP_DIR,
-                              getter_AddRefs(recordingFile));
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  rv = recordingFile->AppendNative(aPageFileName);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  nsAutoCString recordingPath;
-  rv = recordingFile->GetNativePath(recordingPath);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  std::ifstream recording(recordingPath.get(), std::ifstream::binary);
+  std::istringstream recording(std::string(aStoredPage.get<char>(),
+                                           aStoredPage.Size<char>()));
   if (!mPrintTranslator->TranslateRecording(recording)) {
     return NS_ERROR_FAILURE;
   }
 
   rv = mPrintDeviceContext->EndPage();
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
-  recording.close();
-  rv = recordingFile->Remove(/* recursive= */ false);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
   return NS_OK;
 }
 
 bool
 RemotePrintJobParent::RecvFinalizePrint()
 {
   // EndDocument is sometimes called in the child even when BeginDocument has
   // not been called. See bug 1223332.

--- a/layout/printing/ipc/RemotePrintJobParent.h
+++ b/layout/printing/ipc/RemotePrintJobParent.h
@@ -29,17 +29,17 @@ public:
 
   void ActorDestroy(ActorDestroyReason aWhy) final;
 
   bool RecvInitializePrint(const nsString& aDocumentTitle,
                            const nsString& aPrintToFile,
                            const int32_t& aStartPage,
                            const int32_t& aEndPage) final;
 
-  bool RecvProcessPage(const nsCString& aPageFileName) final;
+  bool RecvProcessPage(Shmem&& aStoredPage) final;
 
   bool RecvFinalizePrint() final;
 
   bool RecvAbortPrint(const nsresult& aRv) final;
 
   bool RecvStateChange(const long& aStateFlags,
                        const nsresult& aStatus) final;
 
@@ -65,17 +65,17 @@ public:
 private:
   ~RemotePrintJobParent() final;
 
   nsresult InitializePrintDevice(const nsString& aDocumentTitle,
                                  const nsString& aPrintToFile,
                                  const int32_t& aStartPage,
                                  const int32_t& aEndPage);
 
-  nsresult PrintPage(const nsCString& aPageFileName);
+  nsresult PrintPage(const Shmem& aStoredPage);
 
   nsCOMPtr<nsIPrintSettings> mPrintSettings;
   RefPtr<nsDeviceContext> mPrintDeviceContext;
   UniquePtr<PrintTranslator> mPrintTranslator;
   nsCOMArray<nsIWebProgressListener> mPrintProgressListeners;
 };
 
 } // namespace layout

--- a/widget/nsDeviceContextSpecProxy.cpp
+++ b/widget/nsDeviceContextSpecProxy.cpp
@@ -9,21 +9,18 @@
 #include "gfxASurface.h"
 #include "gfxPlatform.h"
 #include "mozilla/gfx/DrawEventRecorder.h"
 #include "mozilla/gfx/PrintTargetThebes.h"
 #include "mozilla/layout/RemotePrintJobChild.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/Unused.h"
 #include "nsComponentManagerUtils.h"
-#include "nsAppDirectoryServiceDefs.h"
-#include "nsDirectoryServiceUtils.h"
 #include "nsIPrintSession.h"
 #include "nsIPrintSettings.h"
-#include "nsIUUIDGenerator.h"
 
 using mozilla::Unused;
 
 using namespace mozilla;
 using namespace mozilla::gfx;
 
 NS_IMPL_ISUPPORTS(nsDeviceContextSpecProxy, nsIDeviceContextSpec)
 
@@ -132,47 +129,17 @@ nsDeviceContextSpecProxy::GetPrintingSca
   return mRealDeviceContextSpec->GetPrintingScale();
 }
 
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::BeginDocument(const nsAString& aTitle,
                                         const nsAString& aPrintToFileName,
                                         int32_t aStartPage, int32_t aEndPage)
 {
-  nsCOMPtr<nsIFile> recordingFile;
-  nsresult rv = NS_GetSpecialDirectory(NS_APP_CONTENT_PROCESS_TEMP_DIR,
-                                       getter_AddRefs(recordingFile));
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  nsCOMPtr<nsIUUIDGenerator> uuidgen =
-    do_GetService("@mozilla.org/uuid-generator;1", &rv);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  nsID uuid;
-  rv = uuidgen->GenerateUUIDInPlace(&uuid);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  char uuidChars[NSID_LENGTH];
-  uuid.ToProvidedString(uuidChars);
-  mRecorderFile.AssignASCII(uuidChars);
-  rv = recordingFile->AppendNative(mRecorderFile);
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
-
-  nsAutoCString recordingPath;
-  rv = recordingFile->GetNativePath(recordingPath);
-
-  mRecorder = new mozilla::gfx::DrawEventRecorderFile(recordingPath.get());
+  mRecorder = new mozilla::gfx::DrawEventRecorderMemory();
   return mRemotePrintJob->InitializePrint(nsString(aTitle),
                                           nsString(aPrintToFileName),
                                           aStartPage, aEndPage);
 }
 
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::EndDocument()
 {
@@ -185,23 +152,39 @@ nsDeviceContextSpecProxy::AbortDocument(
 {
   Unused << mRemotePrintJob->SendAbortPrint(NS_OK);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::BeginPage()
 {
-  // Reopen the file, if necessary, ready for the next page.
-  mRecorder->OpenAndTruncate();
-
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsDeviceContextSpecProxy::EndPage()
 {
+  // Save the current page recording to shared memory.
+  mozilla::ipc::Shmem storedPage;
+  size_t recordingSize = mRecorder->RecordingSize();
+  if (!mRemotePrintJob->AllocShmem(recordingSize,
+                                   mozilla::ipc::SharedMemory::TYPE_BASIC,
+                                   &storedPage)) {
+    NS_WARNING("Failed to create shared memory for remote printing.");
+    return NS_ERROR_FAILURE;
+  }
+
+  bool success = mRecorder->CopyRecording(storedPage.get<char>(), recordingSize);
+  if (!success) {
+    NS_WARNING("Copying recording to shared memory was not succesful.");
+    return NS_ERROR_FAILURE;
+  }
+
+  // Wipe the recording to free memory. The recorder does not forget which data
+  // backed objects that it has stored.
+  mRecorder->WipeRecording();
+
   // Send the page recording to the parent.
-  mRecorder->Close();
-  mRemotePrintJob->ProcessPage(mRecorderFile);
+  mRemotePrintJob->ProcessPage(storedPage);
 
   return NS_OK;
 }

--- a/widget/nsDeviceContextSpecProxy.h
+++ b/widget/nsDeviceContextSpecProxy.h
@@ -4,23 +4,22 @@
  * 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/. */
 
 #ifndef nsDeviceContextSpecProxy_h
 #define nsDeviceContextSpecProxy_h
 
 #include "nsIDeviceContextSpec.h"
 #include "nsCOMPtr.h"
-#include "nsString.h"
 
 class nsIPrintSession;
 
 namespace mozilla {
 namespace gfx {
-class DrawEventRecorderFile;
+class DrawEventRecorderMemory;
 }
 
 namespace layout {
 class RemotePrintJobChild;
 }
 }
 
 class nsDeviceContextSpecProxy final : public nsIDeviceContextSpec
@@ -53,13 +52,12 @@ public:
 
 private:
   ~nsDeviceContextSpecProxy() {}
 
   nsCOMPtr<nsIPrintSettings> mPrintSettings;
   nsCOMPtr<nsIPrintSession> mPrintSession;
   nsCOMPtr<nsIDeviceContextSpec> mRealDeviceContextSpec;
   RefPtr<mozilla::layout::RemotePrintJobChild> mRemotePrintJob;
-  RefPtr<mozilla::gfx::DrawEventRecorderFile> mRecorder;
-  nsCString mRecorderFile;
+  RefPtr<mozilla::gfx::DrawEventRecorderMemory> mRecorder;
 };
 
 #endif // nsDeviceContextSpecProxy_h

--- a/xpcom/io/nsAppDirectoryServiceDefs.h
+++ b/xpcom/io/nsAppDirectoryServiceDefs.h
@@ -105,14 +105,11 @@
 //
 // New code should avoid writing to the filesystem from the content process
 // and should instead proxy through the parent process whenever possible.
 //
 // At present, all sandboxed content processes use the same directory for
 // NS_APP_CONTENT_PROCESS_TEMP_DIR, but that should not be relied upon.
 //
 #define NS_APP_CONTENT_PROCESS_TEMP_DIR         "ContentTmpD"
-#else
-// Otherwise NS_APP_CONTENT_PROCESS_TEMP_DIR must match NS_OS_TEMP_DIR.
-#define NS_APP_CONTENT_PROCESS_TEMP_DIR         "TmpD"
 #endif // (defined(XP_WIN) || defined(XP_MACOSX)) && defined(MOZ_CONTENT_SANDBOX)
 
 #endif // nsAppDirectoryServiceDefs_h___