diff --git a/content/base/src/nsDocument.cpp b/content/base/src/nsDocument.cpp
index fa5504caa232..0aace7995a4f 100644
--- a/content/base/src/nsDocument.cpp
+++ b/content/base/src/nsDocument.cpp
@@ -66,7 +66,7 @@
 
 #include "nsContentCID.h"
 #include "nsError.h"
-#include "nsIPresShell.h"
+#include "nsPresShell.h"
 #include "nsPresContext.h"
 #include "nsIJSON.h"
 #include "nsThreadUtils.h"
@@ -3322,13 +3322,8 @@ nsDocument::doCreateShell(nsPresContext* aContext,
 
   FillStyleSet(aStyleSet);
 
-  nsCOMPtr<nsIPresShell> shell;
-  nsresult rv = NS_NewPresShell(getter_AddRefs(shell));
-  if (NS_FAILED(rv)) {
-    return rv;
-  }
-
-  rv = shell->Init(this, aContext, aViewManager, aStyleSet, aCompatMode);
+  nsRefPtr<PresShell> shell = new PresShell;
+  nsresult rv = shell->Init(this, aContext, aViewManager, aStyleSet, aCompatMode);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Note: we don't hold a ref to the shell (it holds a ref to us)
@@ -3338,7 +3333,7 @@ nsDocument::doCreateShell(nsPresContext* aContext,
 
   MaybeRescheduleAnimationFrameNotifications();
 
-  shell.swap(*aInstancePtrResult);
+  shell.forget(aInstancePtrResult);
 
   return NS_OK;
 }
diff --git a/layout/base/nsIPresShell.h b/layout/base/nsIPresShell.h
index 6183edc0760f..82d35f2160fc 100644
--- a/layout/base/nsIPresShell.h
+++ b/layout/base/nsIPresShell.h
@@ -1515,11 +1515,4 @@ protected:
   nscoord mMaxLineBoxWidth;
 };
 
-/**
- * Create a new empty presentation shell. Upon success, call Init
- * before attempting to use the shell.
- */
-nsresult
-NS_NewPresShell(nsIPresShell** aInstancePtrResult);
-
 #endif /* nsIPresShell_h___ */
diff --git a/layout/base/nsPresShell.cpp b/layout/base/nsPresShell.cpp
index c168f52a02d8..a6ef89990ac1 100644
--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -686,20 +686,6 @@ nsIPresShell::FrameSelection()
 
 //----------------------------------------------------------------------
 
-nsresult
-NS_NewPresShell(nsIPresShell** aInstancePtrResult)
-{
-  NS_PRECONDITION(nullptr != aInstancePtrResult, "null ptr");
-
-  if (!aInstancePtrResult)
-    return NS_ERROR_NULL_POINTER;
-
-  *aInstancePtrResult = new PresShell();
-
-  NS_ADDREF(*aInstancePtrResult);
-  return NS_OK;
-}
-
 static bool sSynthMouseMove = true;
 
 PresShell::PresShell()
diff --git a/layout/build/nsLayoutCID.h b/layout/build/nsLayoutCID.h
index b07f20cddee2..f44bdadce45f 100644
--- a/layout/build/nsLayoutCID.h
+++ b/layout/build/nsLayoutCID.h
@@ -18,10 +18,6 @@
 #define NS_FRAME_UTIL_CID \
  { 0xa6cf90d5, 0x15b3, 0x11d2,{0x93, 0x2e, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32}}
 
-// {E6FD9940-899D-11d2-8EAE-00805F29F370}
-#define NS_PRESSHELL_CID \
-{ 0xe6fd9940, 0x899d, 0x11d2, { 0x8e, 0xae, 0x0, 0x80, 0x5f, 0x29, 0xf3, 0x70 } }
-
 #define NS_DOMSELECTION_CID \
 {/* {C87A37FC-8109-4ce2-A322-8CDEC925379F}*/ \
  0xc87a37fc, 0x8109, 0x4ce2, { 0xa3, 0x22, 0x8c, 0xde, 0xc9, 0x25, 0x37, 0x9f } }
diff --git a/layout/build/nsLayoutModule.cpp b/layout/build/nsLayoutModule.cpp
index 0eaa7eb28d3b..2e88084e474a 100644
--- a/layout/build/nsLayoutModule.cpp
+++ b/layout/build/nsLayoutModule.cpp
@@ -34,7 +34,6 @@
 #include "nsINodeInfo.h"
 #include "nsIObserver.h"
 #include "nsIObserverService.h"
-#include "nsIPresShell.h"
 #include "nsIScriptNameSpaceManager.h"
 #include "nsISelection.h"
 #include "nsCaret.h"
@@ -517,7 +516,6 @@ MAKE_CTOR(CreateNewLayoutDebugger,        nsILayoutDebugger,           NS_NewLay
 #endif
 
 MAKE_CTOR(CreateNewFrameTraversal,      nsIFrameTraversal,      NS_CreateFrameTraversal)
-MAKE_CTOR(CreateNewPresShell,           nsIPresShell,           NS_NewPresShell)
 MAKE_CTOR(CreateNewBoxObject,           nsIBoxObject,           NS_NewBoxObject)
 
 #ifdef MOZ_XUL
@@ -699,7 +697,6 @@ NS_DEFINE_NAMED_CID(NS_FRAME_UTIL_CID);
 NS_DEFINE_NAMED_CID(NS_LAYOUT_DEBUGGER_CID);
 #endif
 NS_DEFINE_NAMED_CID(NS_FRAMETRAVERSAL_CID);
-NS_DEFINE_NAMED_CID(NS_PRESSHELL_CID);
 NS_DEFINE_NAMED_CID(NS_BOXOBJECT_CID);
 #ifdef MOZ_XUL
 NS_DEFINE_NAMED_CID(NS_LISTBOXOBJECT_CID);
@@ -987,7 +984,6 @@ static const mozilla::Module::CIDEntry kLayoutCIDs[] = {
   { &kNS_LAYOUT_DEBUGGER_CID, false, NULL, CreateNewLayoutDebugger },
 #endif
   { &kNS_FRAMETRAVERSAL_CID, false, NULL, CreateNewFrameTraversal },
-  { &kNS_PRESSHELL_CID, false, NULL, CreateNewPresShell },
   { &kNS_BOXOBJECT_CID, false, NULL, CreateNewBoxObject },
 #ifdef MOZ_XUL
   { &kNS_LISTBOXOBJECT_CID, false, NULL, CreateNewListBoxObject },