--- a/content/media/webaudio/AudioContext.h
+++ b/content/media/webaudio/AudioContext.h
@@ -9,17 +9,17 @@
 
 #include "nsWrapperCache.h"
 #include "nsCycleCollectionParticipant.h"
 #include "mozilla/Attributes.h"
 #include "nsCOMPtr.h"
 #include "EnableWebAudioCheck.h"
 #include "nsAutoPtr.h"
 
-class JSContext;
+struct JSContext;
 class nsIDOMWindow;
 
 namespace mozilla {
 
 class ErrorResult;
 
 namespace dom {
 

--- a/content/media/webaudio/AudioParam.h
+++ b/content/media/webaudio/AudioParam.h
@@ -12,17 +12,17 @@
 #include "nsCycleCollectionParticipant.h"
 #include "nsCOMPtr.h"
 #include "EnableWebAudioCheck.h"
 #include "nsAutoPtr.h"
 #include "AudioContext.h"
 #include "mozilla/dom/TypedArray.h"
 #include "mozilla/Util.h"
 
-class JSContext;
+struct JSContext;
 class nsIDOMWindow;
 
 namespace mozilla {
 
 class ErrorResult;
 
 namespace dom {
 

--- a/dom/bluetooth/BluetoothUtils.h
+++ b/dom/bluetooth/BluetoothUtils.h
@@ -4,18 +4,18 @@
  * 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 mozilla_dom_bluetooth_bluetoothutils_h__
 #define mozilla_dom_bluetooth_bluetoothutils_h__
 
 #include "BluetoothCommon.h"
 
-class JSContext;
-class JSObject;
+struct JSContext;
+struct JSObject;
 
 BEGIN_BLUETOOTH_NAMESPACE
 
 class BluetoothDevice;
 class BluetoothNamedValue;
 
 bool
 SetJsObject(JSContext* aContext,

--- a/dom/network/src/TCPSocketChild.h
+++ b/dom/network/src/TCPSocketChild.h
@@ -6,18 +6,18 @@
 #include "nsITCPSocketChild.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsCOMPtr.h"
 
 #define TCPSOCKETCHILD_CID \
   { 0xa589d96f, 0x7e09, 0x4edf, { 0xa0, 0x1a, 0xeb, 0x49, 0x51, 0xf4, 0x2f, 0x37 } }
 
 class nsITCPSocketInternal;
-class JSContext;
-class JSObject;
+struct JSContext;
+struct JSObject;
 
 namespace mozilla {
 namespace dom {
 
 class TCPSocketChildBase : public nsITCPSocketChild {
 public:
   NS_DECL_CYCLE_COLLECTION_CLASS(TCPSocketChildBase)
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS

--- a/dom/network/src/TCPSocketParent.h
+++ b/dom/network/src/TCPSocketParent.h
@@ -3,18 +3,18 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "mozilla/net/PTCPSocketParent.h"
 #include "nsITCPSocketParent.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsCOMPtr.h"
 #include "nsIDOMTCPSocket.h"
 
-class JSContext;
-class JSObject;
+struct JSContext;
+struct JSObject;
 
 namespace mozilla {
 namespace dom {
 
 class PBrowserParent;
 
 class TCPSocketParent : public mozilla::net::PTCPSocketParent
                       , public nsITCPSocketParent