diff --git a/content/base/public/nsContentUtils.h b/content/base/public/nsContentUtils.h
index 1ec6753e50f..a9b7f9d78ae 100644
--- a/content/base/public/nsContentUtils.h
+++ b/content/base/public/nsContentUtils.h
@@ -79,13 +79,13 @@ static fp_except_t oldmask = fpsetmask(~allmask);
 #include "mozilla/AutoRestore.h"
 #include "nsINode.h"
 #include "nsHashtable.h"
+#include "nsIDOMNode.h"
 
 struct nsNativeKeyEvent; // Don't include nsINativeKeyBindings.h here: it will force strange compilation error!
 
 class nsIDOMScriptObjectFactory;
 class nsIXPConnect;
 class nsIContent;
-class nsIDOMNode;
 class nsIDOMKeyEvent;
 class nsIDocument;
 class nsIDocumentObserver;
@@ -122,7 +122,6 @@ struct JSRuntime;
 class nsIUGenCategory;
 class nsIWidget;
 class nsIDragSession;
-class nsPIDOMWindow;
 class nsIPresShell;
 class nsIXPConnectJSObjectHolder;
 #ifdef MOZ_XTF
diff --git a/content/base/src/nsContentList.h b/content/base/src/nsContentList.h
index c74684567c4..015635b96e9 100644
--- a/content/base/src/nsContentList.h
+++ b/content/base/src/nsContentList.h
@@ -56,7 +56,7 @@
 #include "nsCycleCollectionParticipant.h"
 #include "nsWrapperCache.h"
 #include "nsCRT.h"
-#include "mozilla/dom/Element.h"
+#include "nsHashKeys.h"
 
 // Magic namespace id that means "match all namespaces".  This is
 // negative so it won't collide with actual namespace constants.
@@ -74,6 +74,11 @@ typedef PRBool (*nsContentListMatchFunc)(nsIContent* aContent,
 typedef void (*nsContentListDestroyFunc)(void* aData);
 
 class nsIDocument;
+namespace mozilla {
+namespace dom {
+class Element;
+}
+}
 
 
 class nsBaseContentList : public nsINodeList
diff --git a/content/base/src/nsCopySupport.cpp b/content/base/src/nsCopySupport.cpp
index 3bd37fd41e4..683be579654 100644
--- a/content/base/src/nsCopySupport.cpp
+++ b/content/base/src/nsCopySupport.cpp
@@ -79,6 +79,8 @@
 #include "nsContentUtils.h"
 #include "nsContentCID.h"
 
+#include "mozilla/dom/Element.h"
+
 nsresult NS_NewDomSelection(nsISelection **aDomSelection);
 
 static NS_DEFINE_CID(kCClipboardCID,           NS_CLIPBOARD_CID);
diff --git a/content/base/src/nsFrameLoader.h b/content/base/src/nsFrameLoader.h
index 63cdca3071e..d8e2148252e 100644
--- a/content/base/src/nsFrameLoader.h
+++ b/content/base/src/nsFrameLoader.h
@@ -53,8 +53,8 @@
 #include "nsAutoPtr.h"
 #include "nsFrameMessageManager.h"
 #include "Layers.h"
+#include "nsIContent.h"
 
-class nsIContent;
 class nsIURI;
 class nsSubDocumentFrame;
 class nsIView;
diff --git a/content/base/src/nsImageLoadingContent.cpp b/content/base/src/nsImageLoadingContent.cpp
index 6ee59eb74e2..3d3464d0a0c 100644
--- a/content/base/src/nsImageLoadingContent.cpp
+++ b/content/base/src/nsImageLoadingContent.cpp
@@ -79,6 +79,7 @@
 #include "nsSVGEffects.h"
 
 #include "mozAutoDocUpdate.h"
+#include "mozilla/dom/Element.h"
 
 #ifdef DEBUG_chb
 static void PrintReqURL(imgIRequest* req) {
diff --git a/content/base/src/nsImageLoadingContent.h b/content/base/src/nsImageLoadingContent.h
index b38df99e0c2..5e9312327ef 100644
--- a/content/base/src/nsImageLoadingContent.h
+++ b/content/base/src/nsImageLoadingContent.h
@@ -52,6 +52,7 @@
 #include "nsCOMPtr.h"
 #include "nsContentUtils.h"
 #include "nsString.h"
+#include "nsEventStates.h"
 
 class nsIURI;
 class nsIDocument;
diff --git a/content/base/src/nsNodeInfo.cpp b/content/base/src/nsNodeInfo.cpp
index 4a05d20f558..e9fc75fb2c3 100644
--- a/content/base/src/nsNodeInfo.cpp
+++ b/content/base/src/nsNodeInfo.cpp
@@ -55,6 +55,8 @@
 #include NEW_H
 #include "nsFixedSizeAllocator.h"
 #include "prprf.h"
+#include "nsIDocument.h"
+#include "nsGkAtoms.h"
 
 static const size_t kNodeInfoPoolSizes[] = {
   sizeof(nsNodeInfo)
diff --git a/content/base/src/nsObjectLoadingContent.cpp b/content/base/src/nsObjectLoadingContent.cpp
index 28a7abf5d71..514bfbddf7a 100644
--- a/content/base/src/nsObjectLoadingContent.cpp
+++ b/content/base/src/nsObjectLoadingContent.cpp
@@ -96,6 +96,7 @@
 #include "nsIContentSecurityPolicy.h"
 #include "nsIChannelPolicy.h"
 #include "nsChannelPolicy.h"
+#include "mozilla/dom/Element.h"
 
 #ifdef PR_LOGGING
 static PRLogModuleInfo* gObjectLog = PR_NewLogModule("objlc");
diff --git a/content/base/src/nsTreeWalker.cpp b/content/base/src/nsTreeWalker.cpp
index 3228829a853..2295916fc5f 100644
--- a/content/base/src/nsTreeWalker.cpp
+++ b/content/base/src/nsTreeWalker.cpp
@@ -47,6 +47,8 @@
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeFilter.h"
 #include "nsDOMError.h"
+#include "nsINode.h"
+#include "nsIContent.h"
 
 #include "nsContentUtils.h"
 
diff --git a/content/smil/nsSMILMappedAttribute.cpp b/content/smil/nsSMILMappedAttribute.cpp
index 2092460cdaf..dc1042b9b2b 100644
--- a/content/smil/nsSMILMappedAttribute.cpp
+++ b/content/smil/nsSMILMappedAttribute.cpp
@@ -45,6 +45,7 @@
 #include "nsIDocument.h"
 #include "nsIPresShell.h"
 #include "nsCSSProps.h"
+#include "mozilla/dom/Element.h"
 
 // Callback function, for freeing string buffers stored in property table
 static void
diff --git a/content/xbl/src/nsXBLBinding.cpp b/content/xbl/src/nsXBLBinding.cpp
index b37d537d3b8..d0607e8fdc5 100644
--- a/content/xbl/src/nsXBLBinding.cpp
+++ b/content/xbl/src/nsXBLBinding.cpp
@@ -104,6 +104,8 @@
 #include "nsDOMClassInfo.h"
 #include "nsJSUtils.h"
 
+#include "mozilla/dom/Element.h"
+
 // Helper classes
 
 /***********************************************************************/
diff --git a/content/xbl/src/nsXBLPrototypeBinding.cpp b/content/xbl/src/nsXBLPrototypeBinding.cpp
index fc4b640802e..12a88979886 100644
--- a/content/xbl/src/nsXBLPrototypeBinding.cpp
+++ b/content/xbl/src/nsXBLPrototypeBinding.cpp
@@ -74,6 +74,7 @@
 
 #include "nsIStyleRuleProcessor.h"
 #include "nsXBLResourceLoader.h"
+#include "mozilla/dom/Element.h"
 
 // Helper Classes =====================================================================
 
diff --git a/content/xbl/src/nsXBLService.cpp b/content/xbl/src/nsXBLService.cpp
index 9bc997ab559..01f1ca2fb50 100644
--- a/content/xbl/src/nsXBLService.cpp
+++ b/content/xbl/src/nsXBLService.cpp
@@ -89,6 +89,7 @@
 #endif
 #include "nsIDOMEventListener.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/dom/Element.h"
 
 using namespace mozilla;
 
diff --git a/content/xbl/src/nsXBLWindowKeyHandler.cpp b/content/xbl/src/nsXBLWindowKeyHandler.cpp
index f8da3fce232..7818511bd28 100644
--- a/content/xbl/src/nsXBLWindowKeyHandler.cpp
+++ b/content/xbl/src/nsXBLWindowKeyHandler.cpp
@@ -69,6 +69,7 @@
 #include "nsISelectionController.h"
 #include "nsGUIEvent.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/dom/Element.h"
 
 using namespace mozilla;
 
diff --git a/content/xslt/src/xpath/txMozillaXPathTreeWalker.cpp b/content/xslt/src/xpath/txMozillaXPathTreeWalker.cpp
index d15170bd529..88fb660d32e 100644
--- a/content/xslt/src/xpath/txMozillaXPathTreeWalker.cpp
+++ b/content/xslt/src/xpath/txMozillaXPathTreeWalker.cpp
@@ -54,6 +54,7 @@
 #include "nsUnicharUtils.h"
 #include "nsAttrName.h"
 #include "nsTArray.h"
+#include "mozilla/dom/Element.h"
 
 const PRUint32 kUnknownIndex = PRUint32(-1);
 
diff --git a/content/xul/content/src/nsXULPopupListener.cpp b/content/xul/content/src/nsXULPopupListener.cpp
index 9f6b9f0b929..4c8b77fa273 100644
--- a/content/xul/content/src/nsXULPopupListener.cpp
+++ b/content/xul/content/src/nsXULPopupListener.cpp
@@ -71,6 +71,7 @@
 #include "nsHTMLReflowState.h"
 #include "nsIObjectLoadingContent.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/dom/Element.h"
 
 // for event firing in context menus
 #include "nsPresContext.h"
diff --git a/dom/base/nsDOMNavigationTiming.h b/dom/base/nsDOMNavigationTiming.h
index 821b135d5ee..0577bd6e050 100644
--- a/dom/base/nsDOMNavigationTiming.h
+++ b/dom/base/nsDOMNavigationTiming.h
@@ -46,9 +46,9 @@
 #include "nsCOMPtr.h"
 #include "nsCOMArray.h"
 #include "TimeStamp.h"
+#include "nsIURI.h"
 
 class nsDOMNavigationTimingClock;
-class nsIURI;
 class nsIDocument;
 
 class nsDOMNavigationTiming
diff --git a/dom/base/nsJSUtils.cpp b/dom/base/nsJSUtils.cpp
index 4a1bb9f3ee8..b7888fd49f6 100644
--- a/dom/base/nsJSUtils.cpp
+++ b/dom/base/nsJSUtils.cpp
@@ -57,6 +57,7 @@
 #include "nsCOMPtr.h"
 #include "nsContentUtils.h"
 #include "nsIScriptSecurityManager.h"
+#include "nsPIDOMWindow.h"
 
 #include "nsDOMJSUtils.h" // for GetScriptContextFromJSContext
 
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.cpp b/dom/plugins/base/nsNPAPIPluginInstance.cpp
index 2f80b3f8195..14d244338c6 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.cpp
+++ b/dom/plugins/base/nsNPAPIPluginInstance.cpp
@@ -59,6 +59,7 @@
 #include "nsPluginStreamListenerPeer.h"
 #include "nsSize.h"
 #include "nsNetCID.h"
+#include "nsIContent.h"
 
 using namespace mozilla;
 using namespace mozilla::plugins::parent;
diff --git a/dom/src/notification/nsDesktopNotification.h b/dom/src/notification/nsDesktopNotification.h
index 18ff79b2319..dc548ef8309 100644
--- a/dom/src/notification/nsDesktopNotification.h
+++ b/dom/src/notification/nsDesktopNotification.h
@@ -57,6 +57,7 @@
 
 #include "nsDOMEventTargetHelper.h"
 #include "nsIPrivateDOMEvent.h"
+#include "nsIDocument.h"
 
 class AlertServiceObserver;
 
diff --git a/editor/libeditor/html/nsHTMLEditor.cpp b/editor/libeditor/html/nsHTMLEditor.cpp
index a5086446a57..5f629d01893 100644
--- a/editor/libeditor/html/nsHTMLEditor.cpp
+++ b/editor/libeditor/html/nsHTMLEditor.cpp
@@ -99,6 +99,7 @@
 
 #include "nsIFrame.h"
 #include "nsIParserService.h"
+#include "mozilla/dom/Element.h"
 
 // Some utilities to handle annoying overloading of "A" tag for link and named anchor
 static char hrefText[] = "href";
diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
index af8496f30cf..80ebf0a0c7e 100644
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -195,6 +195,8 @@ static const char sPrintOptionsContractID[]         = "@mozilla.org/gfx/printset
 //switch to page layout
 #include "nsGfxCIID.h"
 
+#include "mozilla/dom/Element.h"
+
 using namespace mozilla;
 
 #ifdef NS_DEBUG
diff --git a/layout/forms/nsButtonFrameRenderer.cpp b/layout/forms/nsButtonFrameRenderer.cpp
index 3180fc180ee..a6f98354030 100644
--- a/layout/forms/nsButtonFrameRenderer.cpp
+++ b/layout/forms/nsButtonFrameRenderer.cpp
@@ -45,6 +45,7 @@
 #include "nsITheme.h"
 #include "nsThemeConstants.h"
 #include "nsEventStates.h"
+#include "mozilla/dom/Element.h"
 
 #define ACTIVE   "active"
 #define HOVER    "hover"
diff --git a/layout/generic/nsSelection.cpp b/layout/generic/nsSelection.cpp
index 6a030782321..2a0af794986 100644
--- a/layout/generic/nsSelection.cpp
+++ b/layout/generic/nsSelection.cpp
@@ -113,6 +113,7 @@ static NS_DEFINE_CID(kFrameTraversalCID, NS_FRAMETRAVERSAL_CID);
 #endif // IBMBIDI
 
 #include "nsDOMError.h"
+#include "mozilla/dom/Element.h"
 
 using namespace mozilla;
 
diff --git a/layout/inspector/src/inDOMUtils.cpp b/layout/inspector/src/inDOMUtils.cpp
index c5fa07d25e0..e7c7ab83631 100644
--- a/layout/inspector/src/inDOMUtils.cpp
+++ b/layout/inspector/src/inDOMUtils.cpp
@@ -59,6 +59,8 @@
 #include "nsEventStateManager.h"
 #include "nsIAtom.h"
 #include "nsIRange.h"
+#include "mozilla/dom/Element.h"
+
 
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/layout/xul/base/src/nsButtonBoxFrame.cpp b/layout/xul/base/src/nsButtonBoxFrame.cpp
index fcadbeaf282..ba2f93cfc6c 100644
--- a/layout/xul/base/src/nsButtonBoxFrame.cpp
+++ b/layout/xul/base/src/nsButtonBoxFrame.cpp
@@ -52,6 +52,8 @@
 #include "nsIDOMElement.h"
 #include "nsDisplayList.h"
 #include "nsContentUtils.h"
+#include "mozilla/dom/Element.h"
+
 
 //
 // NS_NewXULButtonFrame
diff --git a/layout/xul/base/src/nsResizerFrame.cpp b/layout/xul/base/src/nsResizerFrame.cpp
index 5ac7bcb5157..8be50ff9214 100644
--- a/layout/xul/base/src/nsResizerFrame.cpp
+++ b/layout/xul/base/src/nsResizerFrame.cpp
@@ -60,6 +60,8 @@
 #include "nsContentUtils.h"
 #include "nsMenuPopupFrame.h"
 #include "nsIScreenManager.h"
+#include "mozilla/dom/Element.h"
+
 
 //
 // NS_NewResizerFrame
diff --git a/layout/xul/base/src/nsXULTooltipListener.cpp b/layout/xul/base/src/nsXULTooltipListener.cpp
index e074da8f49f..51fb48bf175 100644
--- a/layout/xul/base/src/nsXULTooltipListener.cpp
+++ b/layout/xul/base/src/nsXULTooltipListener.cpp
@@ -61,6 +61,8 @@
 #include "nsIRootBox.h"
 #include "nsEventDispatcher.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/dom/Element.h"
+
 
 using namespace mozilla;
 
diff --git a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
index e1cbf1b5f33..d9a418c8571 100644
--- a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
+++ b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
@@ -88,6 +88,7 @@
 #include "nsIWindowWatcher.h"
 #include "nsIObserverService.h"
 #include "nsFocusManager.h"
+#include "mozilla/dom/Element.h"
 
 #include "nsTypeAheadFind.h"
 
diff --git a/widget/src/xpwidgets/nsNativeTheme.cpp b/widget/src/xpwidgets/nsNativeTheme.cpp
index 8cbd008c497..c39cce42e7f 100644
--- a/widget/src/xpwidgets/nsNativeTheme.cpp
+++ b/widget/src/xpwidgets/nsNativeTheme.cpp
@@ -54,6 +54,7 @@
 #include "nsPIDOMWindow.h"
 #include "nsProgressFrame.h"
 #include "nsMenuFrame.h"
+#include "mozilla/dom/Element.h"
 
 nsNativeTheme::nsNativeTheme()
 : mAnimatedContentTimeout(PR_UINT32_MAX)