diff --git a/dom/xslt/xpath/XPathEvaluator.cpp b/dom/xslt/xpath/XPathEvaluator.cpp
index a638988d9a42..b5e39816df77 100644
--- a/dom/xslt/xpath/XPathEvaluator.cpp
+++ b/dom/xslt/xpath/XPathEvaluator.cpp
@@ -9,7 +9,7 @@
 #include "nsIAtom.h"
 #include "nsXPathExpression.h"
 #include "nsXPathNSResolver.h"
-#include "nsXPathResult.h"
+#include "XPathResult.h"
 #include "nsContentCID.h"
 #include "txExpr.h"
 #include "txExprParser.h"
diff --git a/dom/xslt/xpath/nsXPathResult.cpp b/dom/xslt/xpath/XPathResult.cpp
similarity index 74%
rename from dom/xslt/xpath/nsXPathResult.cpp
rename to dom/xslt/xpath/XPathResult.cpp
index 95d1a4d19b7c..9de54623f768 100644
--- a/dom/xslt/xpath/nsXPathResult.cpp
+++ b/dom/xslt/xpath/XPathResult.cpp
@@ -3,7 +3,7 @@
  * 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/. */
 
-#include "nsXPathResult.h"
+#include "XPathResult.h"
 #include "txExprResult.h"
 #include "txNodeSet.h"
 #include "nsError.h"
@@ -16,18 +16,21 @@
 #include "txXPathTreeWalker.h"
 #include "nsCycleCollectionParticipant.h"
 
-using namespace mozilla::dom;
+DOMCI_DATA(XPathResult, mozilla::dom::XPathResult)
 
-nsXPathResult::nsXPathResult() : mDocument(nullptr),
-                                 mCurrentPos(0),
-                                 mResultType(ANY_TYPE),
-                                 mInvalidIteratorState(true),
-                                 mBooleanResult(false),
-                                 mNumberResult(0)
+namespace mozilla {
+namespace dom {
+
+XPathResult::XPathResult() : mDocument(nullptr),
+                             mCurrentPos(0),
+                             mResultType(ANY_TYPE),
+                             mInvalidIteratorState(true),
+                             mBooleanResult(false),
+                             mNumberResult(0)
 {
 }
 
-nsXPathResult::nsXPathResult(const nsXPathResult &aResult)
+XPathResult::XPathResult(const XPathResult &aResult)
     : mResult(aResult.mResult),
       mResultNodes(aResult.mResultNodes),
       mDocument(aResult.mDocument),
@@ -41,30 +44,28 @@ nsXPathResult::nsXPathResult(const nsXPathResult &aResult)
     }
 }
 
-nsXPathResult::~nsXPathResult()
+XPathResult::~XPathResult()
 {
     RemoveObserver();
 }
 
-NS_IMPL_CYCLE_COLLECTION_CLASS(nsXPathResult)
+NS_IMPL_CYCLE_COLLECTION_CLASS(XPathResult)
 
-NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsXPathResult)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(XPathResult)
     {
         tmp->RemoveObserver();
     }
     NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocument)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsXPathResult)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(XPathResult)
     NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDocument)
     NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResultNodes)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(nsXPathResult)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(nsXPathResult)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(XPathResult)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(XPathResult)
 
-DOMCI_DATA(XPathResult, nsXPathResult)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsXPathResult)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(XPathResult)
     NS_INTERFACE_MAP_ENTRY(nsIDOMXPathResult)
     NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
     NS_INTERFACE_MAP_ENTRY(nsIXPathResult)
@@ -73,7 +74,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsXPathResult)
 NS_INTERFACE_MAP_END
 
 void
-nsXPathResult::RemoveObserver()
+XPathResult::RemoveObserver()
 {
     if (mDocument) {
         mDocument->RemoveMutationObserver(this);
@@ -81,7 +82,7 @@ nsXPathResult::RemoveObserver()
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetResultType(uint16_t *aResultType)
+XPathResult::GetResultType(uint16_t *aResultType)
 {
     *aResultType = mResultType;
 
@@ -89,7 +90,7 @@ nsXPathResult::GetResultType(uint16_t *aResultType)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetNumberValue(double *aNumberValue)
+XPathResult::GetNumberValue(double *aNumberValue)
 {
     if (mResultType != NUMBER_TYPE) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -101,7 +102,7 @@ nsXPathResult::GetNumberValue(double *aNumberValue)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetStringValue(nsAString &aStringValue)
+XPathResult::GetStringValue(nsAString &aStringValue)
 {
     if (mResultType != STRING_TYPE) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -113,7 +114,7 @@ nsXPathResult::GetStringValue(nsAString &aStringValue)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetBooleanValue(bool *aBooleanValue)
+XPathResult::GetBooleanValue(bool *aBooleanValue)
 {
     if (mResultType != BOOLEAN_TYPE) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -125,7 +126,7 @@ nsXPathResult::GetBooleanValue(bool *aBooleanValue)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetSingleNodeValue(nsIDOMNode **aSingleNodeValue)
+XPathResult::GetSingleNodeValue(nsIDOMNode **aSingleNodeValue)
 {
     if (!isNode()) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -142,7 +143,7 @@ nsXPathResult::GetSingleNodeValue(nsIDOMNode **aSingleNodeValue)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetInvalidIteratorState(bool *aInvalidIteratorState)
+XPathResult::GetInvalidIteratorState(bool *aInvalidIteratorState)
 {
     *aInvalidIteratorState = isIterator() && mInvalidIteratorState;
 
@@ -150,7 +151,7 @@ nsXPathResult::GetInvalidIteratorState(bool *aInvalidIteratorState)
 }
 
 NS_IMETHODIMP
-nsXPathResult::GetSnapshotLength(uint32_t *aSnapshotLength)
+XPathResult::GetSnapshotLength(uint32_t *aSnapshotLength)
 {
     if (!isSnapshot()) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -162,7 +163,7 @@ nsXPathResult::GetSnapshotLength(uint32_t *aSnapshotLength)
 }
 
 NS_IMETHODIMP
-nsXPathResult::IterateNext(nsIDOMNode **aResult)
+XPathResult::IterateNext(nsIDOMNode **aResult)
 {
     if (!isIterator()) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -187,7 +188,7 @@ nsXPathResult::IterateNext(nsIDOMNode **aResult)
 }
 
 NS_IMETHODIMP
-nsXPathResult::SnapshotItem(uint32_t aIndex, nsIDOMNode **aResult)
+XPathResult::SnapshotItem(uint32_t aIndex, nsIDOMNode **aResult)
 {
     if (!isSnapshot()) {
         return NS_ERROR_DOM_TYPE_ERR;
@@ -199,7 +200,7 @@ nsXPathResult::SnapshotItem(uint32_t aIndex, nsIDOMNode **aResult)
 }
 
 void
-nsXPathResult::NodeWillBeDestroyed(const nsINode* aNode)
+XPathResult::NodeWillBeDestroyed(const nsINode* aNode)
 {
     nsCOMPtr<nsIMutationObserver> kungFuDeathGrip(this);
     // Set to null to avoid unregistring unnecessarily
@@ -209,54 +210,54 @@ nsXPathResult::NodeWillBeDestroyed(const nsINode* aNode)
 }
 
 void
-nsXPathResult::CharacterDataChanged(nsIDocument* aDocument,
-                                    nsIContent *aContent,
-                                    CharacterDataChangeInfo* aInfo)
+XPathResult::CharacterDataChanged(nsIDocument* aDocument,
+                                  nsIContent *aContent,
+                                  CharacterDataChangeInfo* aInfo)
 {
     Invalidate(aContent);
 }
 
 void
-nsXPathResult::AttributeChanged(nsIDocument* aDocument,
-                                Element* aElement,
-                                int32_t aNameSpaceID,
-                                nsIAtom* aAttribute,
-                                int32_t aModType)
+XPathResult::AttributeChanged(nsIDocument* aDocument,
+                              Element* aElement,
+                              int32_t aNameSpaceID,
+                              nsIAtom* aAttribute,
+                              int32_t aModType)
 {
     Invalidate(aElement);
 }
 
 void
-nsXPathResult::ContentAppended(nsIDocument* aDocument,
-                               nsIContent* aContainer,
-                               nsIContent* aFirstNewContent,
-                               int32_t aNewIndexInContainer)
+XPathResult::ContentAppended(nsIDocument* aDocument,
+                             nsIContent* aContainer,
+                             nsIContent* aFirstNewContent,
+                             int32_t aNewIndexInContainer)
 {
     Invalidate(aContainer);
 }
 
 void
-nsXPathResult::ContentInserted(nsIDocument* aDocument,
-                               nsIContent* aContainer,
-                               nsIContent* aChild,
-                               int32_t aIndexInContainer)
+XPathResult::ContentInserted(nsIDocument* aDocument,
+                             nsIContent* aContainer,
+                             nsIContent* aChild,
+                             int32_t aIndexInContainer)
 {
     Invalidate(aContainer);
 }
 
 void
-nsXPathResult::ContentRemoved(nsIDocument* aDocument,
-                              nsIContent* aContainer,
-                              nsIContent* aChild,
-                              int32_t aIndexInContainer,
-                              nsIContent* aPreviousSibling)
+XPathResult::ContentRemoved(nsIDocument* aDocument,
+                            nsIContent* aContainer,
+                            nsIContent* aChild,
+                            int32_t aIndexInContainer,
+                            nsIContent* aPreviousSibling)
 {
     Invalidate(aContainer);
 }
 
 nsresult
-nsXPathResult::SetExprResult(txAExprResult* aExprResult, uint16_t aResultType,
-                             nsINode* aContextNode)
+XPathResult::SetExprResult(txAExprResult* aExprResult, uint16_t aResultType,
+                           nsINode* aContextNode)
 {
     MOZ_ASSERT(aExprResult);
 
@@ -347,7 +348,7 @@ nsXPathResult::SetExprResult(txAExprResult* aExprResult, uint16_t aResultType,
 }
 
 void
-nsXPathResult::Invalidate(const nsIContent* aChangeRoot)
+XPathResult::Invalidate(const nsIContent* aChangeRoot)
 {
     nsCOMPtr<nsINode> contextNode = do_QueryReferent(mContextNode);
     if (contextNode && aChangeRoot && aChangeRoot->GetBindingParent()) {
@@ -381,7 +382,7 @@ nsXPathResult::Invalidate(const nsIContent* aChangeRoot)
 }
 
 nsresult
-nsXPathResult::GetExprResult(txAExprResult** aExprResult)
+XPathResult::GetExprResult(txAExprResult** aExprResult)
 {
     if (isIterator() && mInvalidIteratorState) {
         return NS_ERROR_DOM_INVALID_STATE_ERR;
@@ -418,7 +419,7 @@ nsXPathResult::GetExprResult(txAExprResult** aExprResult)
 }
 
 nsresult
-nsXPathResult::Clone(nsIXPathResult **aResult)
+XPathResult::Clone(nsIXPathResult **aResult)
 {
     *aResult = nullptr;
 
@@ -426,7 +427,7 @@ nsXPathResult::Clone(nsIXPathResult **aResult)
         return NS_ERROR_DOM_INVALID_STATE_ERR;
     }
 
-    nsCOMPtr<nsIXPathResult> result = new nsXPathResult(*this);
+    nsCOMPtr<nsIXPathResult> result = new XPathResult(*this);
     if (!result) {
         return NS_ERROR_OUT_OF_MEMORY;
     }
@@ -435,3 +436,6 @@ nsXPathResult::Clone(nsIXPathResult **aResult)
 
     return NS_OK;
 }
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/xslt/xpath/nsXPathResult.h b/dom/xslt/xpath/XPathResult.h
similarity index 86%
rename from dom/xslt/xpath/nsXPathResult.h
rename to dom/xslt/xpath/XPathResult.h
index 9992580385ee..dfa9b15be91d 100644
--- a/dom/xslt/xpath/nsXPathResult.h
+++ b/dom/xslt/xpath/XPathResult.h
@@ -3,8 +3,8 @@
  * 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 nsXPathResult_h__
-#define nsXPathResult_h__
+#ifndef mozilla_dom_XPathResult_h
+#define mozilla_dom_XPathResult_h
 
 #include "txExprResult.h"
 #include "nsIDOMXPathResult.h"
@@ -34,21 +34,24 @@ public:
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsIXPathResult, NS_IXPATHRESULT_IID)
 
+namespace mozilla {
+namespace dom {
+
 /**
  * A class for evaluating an XPath expression string
  */
-class nsXPathResult MOZ_FINAL : public nsIDOMXPathResult,
-                                public nsStubMutationObserver,
-                                public nsIXPathResult
+class XPathResult MOZ_FINAL : public nsIDOMXPathResult,
+                              public nsStubMutationObserver,
+                              public nsIXPathResult
 {
 public:
-    nsXPathResult();
-    nsXPathResult(const nsXPathResult &aResult);
-    ~nsXPathResult();
+    XPathResult();
+    XPathResult(const XPathResult &aResult);
+    ~XPathResult();
 
     // nsISupports interface
     NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-    NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsXPathResult, nsIDOMXPathResult)
+    NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(XPathResult, nsIDOMXPathResult)
 
     // nsIDOMXPathResult interface
     NS_DECL_NSIDOMXPATHRESULT
@@ -110,4 +113,7 @@ private:
     nsString mStringResult;
 };
 
-#endif
+} // namespace dom
+} // namespace mozilla
+
+#endif /* mozilla_dom_XPathResult_h */
diff --git a/dom/xslt/xpath/moz.build b/dom/xslt/xpath/moz.build
index 21d43ebdc4d7..822d06c8127a 100644
--- a/dom/xslt/xpath/moz.build
+++ b/dom/xslt/xpath/moz.build
@@ -6,12 +6,12 @@
 
 EXPORTS.mozilla.dom += [
     'XPathEvaluator.h',
+    'XPathResult.h',
 ]
 
 UNIFIED_SOURCES += [
     'nsXPathExpression.cpp',
     'nsXPathNSResolver.cpp',
-    'nsXPathResult.cpp',
     'txBooleanExpr.cpp',
     'txBooleanResult.cpp',
     'txCoreFunctionCall.cpp',
@@ -47,6 +47,7 @@ UNIFIED_SOURCES += [
     'txXPathOptimizer.cpp',
     'txXPCOMExtensionFunction.cpp',
     'XPathEvaluator.cpp',
+    'XPathResult.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
diff --git a/dom/xslt/xpath/nsXPathExpression.cpp b/dom/xslt/xpath/nsXPathExpression.cpp
index 7a5cc13a79ee..15afb1b3fab7 100644
--- a/dom/xslt/xpath/nsXPathExpression.cpp
+++ b/dom/xslt/xpath/nsXPathExpression.cpp
@@ -11,10 +11,11 @@
 #include "nsIDOMCharacterData.h"
 #include "nsDOMClassInfoID.h"
 #include "nsIDOMDocument.h"
-#include "nsXPathResult.h"
+#include "XPathResult.h"
 #include "txURIUtils.h"
 #include "txXPathTreeWalker.h"
 
+using namespace mozilla::dom;
 using mozilla::Move;
 
 NS_IMPL_CYCLE_COLLECTION(nsXPathExpression, mDocument)
@@ -140,7 +141,7 @@ nsXPathExpression::EvaluateWithContext(nsIDOMNode *aContextNode,
     nsCOMPtr<nsIXPathResult> xpathResult = do_QueryInterface(aInResult);
     if (!xpathResult) {
         // Either no aInResult or not one of ours.
-        xpathResult = new nsXPathResult();
+        xpathResult = new XPathResult();
         NS_ENSURE_TRUE(xpathResult, NS_ERROR_OUT_OF_MEMORY);
     }
     rv = xpathResult->SetExprResult(exprResult, resultType, context);
diff --git a/dom/xslt/xslt/txMozillaXSLTProcessor.cpp b/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
index d3c8337399d7..b9fdd2b00e4a 100644
--- a/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
+++ b/dom/xslt/xslt/txMozillaXSLTProcessor.cpp
@@ -20,7 +20,7 @@
 #include "nsIStringBundle.h"
 #include "nsIURI.h"
 #include "nsNetUtil.h"
-#include "nsXPathResult.h"
+#include "XPathResult.h"
 #include "txExecutionState.h"
 #include "txMozillaTextOutput.h"
 #include "txMozillaXMLOutput.h"
@@ -809,7 +809,7 @@ txMozillaXSLTProcessor::SetParameter(const nsAString & aNamespaceURI,
                     }
                 }
 
-                // Clone the nsXPathResult so that mutations don't affect this
+                // Clone the XPathResult so that mutations don't affect this
                 // variable.
                 nsCOMPtr<nsIXPathResult> clone;
                 rv = xpathResult->Clone(getter_AddRefs(clone));