diff --git a/dom/ipc/ContentChild.cpp b/dom/ipc/ContentChild.cpp
index d0ece243f75..e01be71c85d 100644
--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -71,6 +71,7 @@
 #include "nsLayoutStylesheetCache.h"
 #include "nsIJSRuntimeService.h"
 #include "nsThreadManager.h"
+#include "nsAnonymousTemporaryFile.h"
 
 #include "IHistory.h"
 #include "nsNetUtil.h"
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 1ae706eef64..acdc155e1af 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -66,6 +66,7 @@
 #include "mozilla/Services.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/unused.h"
+#include "nsAnonymousTemporaryFile.h"
 #include "nsAppRunner.h"
 #include "nsAutoPtr.h"
 #include "nsCDefaultURIFixup.h"
@@ -118,6 +119,8 @@
 #include "nsIDocShell.h"
 #include "mozilla/net/NeckoMessageUtils.h"
 #include "gfxPrefs.h"
+#include "prio.h"
+#include "private/pprio.h"
 
 #if defined(ANDROID) || defined(LINUX)
 #include "nsSystemInfo.h"
@@ -3655,6 +3658,21 @@ ContentParent::RecvBackUpXResources(const FileDescriptor& aXSocketFd)
     return true;
 }
 
+bool
+ContentParent::RecvOpenAnonymousTemporaryFile(FileDescriptor *aFD)
+{
+    PRFileDesc *prfd;
+    nsresult rv = NS_OpenAnonymousTemporaryFile(&prfd);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+        return false;
+    }
+    *aFD = FileDescriptor::PlatformHandleType(PR_FileDesc2NativeHandle(prfd));
+    // The FileDescriptor object owns a duplicate of the file handle; we
+    // must close the original (and clean up the NSPR descriptor).
+    PR_Close(prfd);
+    return true;
+}
+
 PFileDescriptorSetParent*
 ContentParent::AllocPFileDescriptorSetParent(const FileDescriptor& aFD)
 {
diff --git a/dom/ipc/ContentParent.h b/dom/ipc/ContentParent.h
index be8034d0cd0..6c08a5787b6 100644
--- a/dom/ipc/ContentParent.h
+++ b/dom/ipc/ContentParent.h
@@ -610,6 +610,9 @@ private:
     virtual bool
     RecvBackUpXResources(const FileDescriptor& aXSocketFd) MOZ_OVERRIDE;
 
+    virtual bool
+    RecvOpenAnonymousTemporaryFile(FileDescriptor* aFD) MOZ_OVERRIDE;
+
     virtual PFileDescriptorSetParent*
     AllocPFileDescriptorSetParent(const mozilla::ipc::FileDescriptor&) MOZ_OVERRIDE;
 
diff --git a/dom/ipc/PContent.ipdl b/dom/ipc/PContent.ipdl
index 4dc5fe71432..5be7469ec58 100644
--- a/dom/ipc/PContent.ipdl
+++ b/dom/ipc/PContent.ipdl
@@ -646,6 +646,8 @@ parent:
      */
     BackUpXResources(FileDescriptor aXSocketFd);
 
+    sync OpenAnonymousTemporaryFile() returns (FileDescriptor aFD);
+
 both:
      AsyncMessage(nsString aMessage, ClonedMessageData aData,
                   CpowEntry[] aCpows, Principal aPrincipal);
diff --git a/xpcom/io/nsAnonymousTemporaryFile.cpp b/xpcom/io/nsAnonymousTemporaryFile.cpp
index b71a6e7aad8..b76962e40da 100644
--- a/xpcom/io/nsAnonymousTemporaryFile.cpp
+++ b/xpcom/io/nsAnonymousTemporaryFile.cpp
@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 
+#include "mozilla/dom/ContentChild.h"
 #include "nsAnonymousTemporaryFile.h"
 #include "nsDirectoryServiceUtils.h"
 #include "nsDirectoryServiceDefs.h"
@@ -11,6 +12,8 @@
 #include "nsCOMPtr.h"
 #include "nsString.h"
 #include "nsAppDirectoryServiceDefs.h"
+#include "prio.h"
+#include "private/pprio.h"
 
 #ifdef XP_WIN
 #include "nsIObserver.h"
@@ -23,9 +26,9 @@
 #include "nsITimer.h"
 #include "nsCRT.h"
 
-using namespace mozilla;
 #endif
 
+using namespace mozilla;
 
 // We store the temp files in the system temp dir.
 //
@@ -84,8 +87,18 @@ NS_OpenAnonymousTemporaryFile(PRFileDesc** aOutFileDesc)
   if (NS_WARN_IF(!aOutFileDesc)) {
     return NS_ERROR_INVALID_ARG;
   }
-  nsresult rv;
 
+  if (dom::ContentChild* child = dom::ContentChild::GetSingleton()) {
+    ipc::FileDescriptor fd;
+    DebugOnly<bool> succeeded = child->SendOpenAnonymousTemporaryFile(&fd);
+    // The child process should already have been terminated if the
+    // IPC had failed.
+    MOZ_ASSERT(succeeded);
+    *aOutFileDesc = PR_ImportFile(PROsfd(fd.PlatformHandle()));
+    return NS_OK;
+  }
+
+  nsresult rv;
   nsCOMPtr<nsIFile> tmpFile;
   rv = GetTempDir(getter_AddRefs(tmpFile));
   if (NS_WARN_IF(NS_FAILED(rv))) {