diff --git a/content/xslt/src/xpath/nsXPathResult.cpp b/content/xslt/src/xpath/nsXPathResult.cpp
index c88c4a1a004f..4f9b843b6a67 100644
--- a/content/xslt/src/xpath/nsXPathResult.cpp
+++ b/content/xslt/src/xpath/nsXPathResult.cpp
@@ -45,8 +45,8 @@
 #include "nsIContent.h"
 #include "nsIDOMClassInfo.h"
 #include "nsIDOMNode.h"
-#include "nsSupportsArray.h"
 #include "nsXPathException.h"
+#include "nsIDOMDocument.h"
 
 NS_IMPL_ADDREF(nsXPathResult)
 NS_IMPL_RELEASE(nsXPathResult)
@@ -151,9 +151,9 @@ nsXPathResult::GetSnapshotLength(PRUint32 *aSnapshotLength)
         return NS_ERROR_DOM_TYPE_ERR;
 
     NS_ENSURE_ARG(aSnapshotLength);
-    if (mElements)
-        return mElements->Count(aSnapshotLength);
     *aSnapshotLength = 0;
+    if (mElements)
+        *aSnapshotLength = mElements->Count();
     return NS_OK;
 }
 
@@ -171,14 +171,10 @@ nsXPathResult::IterateNext(nsIDOMNode **aResult)
         return NS_ERROR_DOM_INVALID_STATE_ERR;
 
     NS_ENSURE_ARG(aResult);
-    if (mElements) {
-        PRUint32 count;
-        mElements->Count(&count);
-        if (mCurrentPos < count) {
-            return mElements->QueryElementAt(mCurrentPos++,
-                                             NS_GET_IID(nsIDOMNode),
-                                             (void**)aResult);
-        }
+    if (mElements && mCurrentPos < mElements->Count()) {
+        *aResult = mElements->ObjectAt(mCurrentPos++);
+        NS_ADDREF(*aResult);
+        return NS_OK;
     }
     *aResult = nsnull;
     return NS_OK;
@@ -192,14 +188,10 @@ nsXPathResult::SnapshotItem(PRUint32 aIndex, nsIDOMNode **aResult)
         return NS_ERROR_DOM_TYPE_ERR;
 
     NS_ENSURE_ARG(aResult);
-    if (mElements) {
-        PRUint32 count;
-        mElements->Count(&count);
-        if (aIndex < count) {
-            return mElements->QueryElementAt(aIndex,
-                                             NS_GET_IID(nsIDOMNode),
-                                             (void**)aResult);
-        }
+    if (mElements && aIndex < mElements->Count()) {
+        *aResult = mElements->ObjectAt(aIndex);
+        NS_ADDREF(*aResult);
+        return NS_OK;
     }
     *aResult = nsnull;
     return NS_OK;
@@ -316,23 +308,28 @@ nsXPathResult::SetExprResult(ExprResult* aExprResult, PRUint16 aResultType)
             if (count == 0)
                 return NS_OK;
 
-            NS_NewISupportsArray(&mElements);
+            mElements = new nsCOMArray<nsIDOMNode>;
             NS_ENSURE_TRUE(mElements, NS_ERROR_OUT_OF_MEMORY);
 
-            nsISupports* mozNode = nsnull;
+            nsCOMPtr<nsIDOMNode> node;
             int i;
             for (i = 0; i < count; ++i) {
-                mozNode = nodeSet->get(i)->getNSObj();
-                mElements->AppendElement(mozNode);
-                NS_ADDREF(mozNode);
+                node = do_QueryInterface(nodeSet->get(i)->getNSObj());
+                NS_ASSERTION(node, "node isn't an nsIDOMNode");
+                mElements->AppendObject(node);
             }
+
+            // If we support the document() function in DOM-XPath we need to
+            // observe all documents that we have resultnodes in.
             if (mResultType == UNORDERED_NODE_ITERATOR_TYPE ||
                 mResultType == ORDERED_NODE_ITERATOR_TYPE) {
-                nsCOMPtr<nsIContent> content = do_QueryInterface(mozNode);
-                if (content)
-                    content->GetDocument(*getter_AddRefs(mDocument));
+                nsCOMPtr<nsIDOMDocument> document;
+                node->GetOwnerDocument(getter_AddRefs(document));
+                if (document)
+                    mDocument = do_QueryInterface(document);
                 else
-                    mDocument = do_QueryInterface(mozNode);
+                    mDocument = do_QueryInterface(node);
+
                 NS_ASSERTION(mDocument, "We need a document!");
                 if (mDocument)
                     mDocument->AddObserver(this);
@@ -367,7 +364,7 @@ nsXPathResult::Reset()
              mResultType == ORDERED_NODE_ITERATOR_TYPE ||
              mResultType == UNORDERED_NODE_SNAPSHOT_TYPE ||
              mResultType == ORDERED_NODE_SNAPSHOT_TYPE) {
-        NS_IF_RELEASE(mElements);
+        delete mElements;
         mCurrentPos = 0;
     }
     else if (mResultType == FIRST_ORDERED_NODE_TYPE ||
diff --git a/content/xslt/src/xpath/nsXPathResult.h b/content/xslt/src/xpath/nsXPathResult.h
index 3c0d8ccc5fc0..ffcfb9fdaf89 100644
--- a/content/xslt/src/xpath/nsXPathResult.h
+++ b/content/xslt/src/xpath/nsXPathResult.h
@@ -44,10 +44,10 @@
 #include "nsIDocument.h"
 #include "nsIDocumentObserver.h"
 #include "nsCOMPtr.h"
+#include "nsCOMArray.h"
 
 class ExprResult;
 class String;
-class nsISupportsArray;
 
 // {15b9b301-2012-11d6-a7f2-e6d0a678995c}
 #define NS_IXPATHRESULT_IID \
@@ -93,7 +93,7 @@ private:
         String* mStringValue;
         PRBool mBooleanValue;
         nsIDOMNode* mNode;
-        nsISupportsArray* mElements;
+        nsCOMArray<nsIDOMNode>* mElements;
     };
     nsCOMPtr<nsIDocument> mDocument;
     PRUint32 mCurrentPos;
diff --git a/content/xslt/src/xslt/txMozillaXMLOutput.cpp b/content/xslt/src/xslt/txMozillaXMLOutput.cpp
index 13d0e38144a5..ad6bb1c07b04 100644
--- a/content/xslt/src/xslt/txMozillaXMLOutput.cpp
+++ b/content/xslt/src/xslt/txMozillaXMLOutput.cpp
@@ -318,11 +318,7 @@ void txMozillaXMLOutput::processingInstruction(const String& aTarget, const Stri
 
 void txMozillaXMLOutput::removeScriptElement(nsIDOMHTMLScriptElement *aElement)
 {
-    if (mScriptElements) {
-        PRInt32 index = mScriptElements->IndexOf(aElement);
-        if (index > -1)
-            mScriptElements->RemoveElementAt(index);
-    }
+    mScriptElements.RemoveObject(aElement);
 }
 
 void txMozillaXMLOutput::startDocument()
@@ -547,11 +543,7 @@ void txMozillaXMLOutput::endHTMLElement(nsIDOMElement* aElement,
         nsCOMPtr<nsIDOMHTMLScriptElement> scriptElement =
             do_QueryInterface(mCurrentNode);
         NS_ASSERTION(scriptElement, "Need script element");
-        if (!mScriptElements)
-            NS_NewISupportsArray(getter_AddRefs(mScriptElements));
-        NS_ASSERTION(mScriptElements, "Can't create array");
-        if (mScriptElements)
-            mScriptElements->AppendElement(scriptElement);
+        mScriptElements.AppendObject(scriptElement);
     }
     // Set document title
     else if (mCreatingNewDocument &&
@@ -776,12 +768,8 @@ txMozillaXMLOutput::SignalTransformEnd()
         return;
     }
 
-    if (mScriptElements) {
-        PRUint32 scriptCount = 0;
-        mScriptElements->Count(&scriptCount);
-        if (scriptCount != 0) {
-            return;
-        }
+    if (mScriptElements.Count() > 0) {
+        return;
     }
 
     // Make sure that we don't get deleted while this function is executed and
diff --git a/content/xslt/src/xslt/txMozillaXMLOutput.h b/content/xslt/src/xslt/txMozillaXMLOutput.h
index 16ddbc4e4e83..86896690b6d2 100644
--- a/content/xslt/src/xslt/txMozillaXMLOutput.h
+++ b/content/xslt/src/xslt/txMozillaXMLOutput.h
@@ -47,9 +47,9 @@
 #include "nsIScriptLoaderObserver.h"
 #include "nsIStyleSheetLinkingElement.h"
 #include "nsString.h"
-#include "nsSupportsArray.h"
 #include "nsWeakPtr.h"
 #include "txOutputFormat.h"
+#include "nsCOMArray.h"
 
 class txMozillaXMLOutput : public txIOutputXMLEventHandler,
                            public nsIScriptLoaderObserver
@@ -191,7 +191,7 @@ private:
     PRUint32 mBadChildLevel;
     nsCString mRefreshString;
 
-    nsCOMPtr<nsISupportsArray> mScriptElements;
+    nsCOMArray<nsIDOMHTMLScriptElement> mScriptElements;
 
     nsAutoString mText;