diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 788fb5dc1e5c..c8feeec4a511 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,25 @@
+2014-12-16  Anders Carlsson  <andersca@apple.com>
+
+        Put some common code in StorageNamespaceProvider
+        https://bugs.webkit.org/show_bug.cgi?id=139682
+
+        Reviewed by Tim Horton.
+
+        We have code in two places that gets the local storage area from a given document,
+        choosing either the local storage namespace or the transient local storage namespace.
+        Move it to StorageNamespaceProvider::localStorageArea.
+
+        * bindings/js/ScriptController.cpp:
+        * inspector/InspectorDOMStorageAgent.cpp:
+        (WebCore::InspectorDOMStorageAgent::findStorageArea):
+        * page/DOMWindow.cpp:
+        (WebCore::DOMWindow::localStorage):
+        * page/Navigator.cpp:
+        * storage/StorageNamespaceProvider.cpp:
+        (WebCore::StorageNamespaceProvider::localStorageArea):
+        (WebCore::StorageNamespaceProvider::localStorageNamespace):
+        * storage/StorageNamespaceProvider.h:
+
 2014-12-16  Anders Carlsson  <andersca@apple.com>
 
         Add FeatureCounterKeys.h to the Xcode project.
diff --git a/Source/WebCore/bindings/js/ScriptController.cpp b/Source/WebCore/bindings/js/ScriptController.cpp
index c99adfdee0b3..702144c66441 100644
--- a/Source/WebCore/bindings/js/ScriptController.cpp
+++ b/Source/WebCore/bindings/js/ScriptController.cpp
@@ -43,7 +43,6 @@
 #include "ScriptSourceCode.h"
 #include "ScriptableDocumentParser.h"
 #include "Settings.h"
-#include "StorageNamespace.h"
 #include "UserGestureIndicator.h"
 #include "WebCoreJSClientData.h"
 #include "npruntime_impl.h"
diff --git a/Source/WebCore/inspector/InspectorDOMStorageAgent.cpp b/Source/WebCore/inspector/InspectorDOMStorageAgent.cpp
index 41baf0a09a05..d7c5ea30fcd4 100644
--- a/Source/WebCore/inspector/InspectorDOMStorageAgent.cpp
+++ b/Source/WebCore/inspector/InspectorDOMStorageAgent.cpp
@@ -45,7 +45,6 @@
 #include "PageGroup.h"
 #include "SecurityOrigin.h"
 #include "Storage.h"
-#include "StorageNamespace.h"
 #include "StorageNamespaceProvider.h"
 #include "VoidCallback.h"
 #include <inspector/InspectorFrontendDispatchers.h>
@@ -201,14 +200,7 @@ PassRefPtr<StorageArea> InspectorDOMStorageAgent::findStorageArea(ErrorString& e
         return nullptr;
     }
 
-    Page* page = m_pageAgent->page();
-    Document* document = targetFrame->document();
-    if (isLocalStorage) {
-        if (document->securityOrigin()->canAccessLocalStorage(document->topOrigin()))
-            return page->storageNamespaceProvider().localStorageNamespace().storageArea(document->securityOrigin());
-        return page->storageNamespaceProvider().transientLocalStorageNamespace(*document->topOrigin()).storageArea(document->securityOrigin());
-    }
-    return page->sessionStorage()->storageArea(document->securityOrigin());
+    return m_pageAgent->page()->storageNamespaceProvider().localStorageArea(*targetFrame->document());
 }
 
 } // namespace WebCore
diff --git a/Source/WebCore/page/DOMWindow.cpp b/Source/WebCore/page/DOMWindow.cpp
index 3b83e796b29e..16ab50d45e18 100644
--- a/Source/WebCore/page/DOMWindow.cpp
+++ b/Source/WebCore/page/DOMWindow.cpp
@@ -856,12 +856,7 @@ Storage* DOMWindow::localStorage(ExceptionCode& ec) const
     if (!page->settings().localStorageEnabled())
         return nullptr;
 
-    RefPtr<StorageArea> storageArea;
-
-    if (document->securityOrigin()->canAccessLocalStorage(document->topOrigin()))
-        storageArea = page->storageNamespaceProvider().localStorageNamespace().storageArea(document->securityOrigin());
-    else
-        storageArea = page->storageNamespaceProvider().transientLocalStorageNamespace(*document->topOrigin()).storageArea(document->securityOrigin());
+    RefPtr<StorageArea> storageArea = page->storageNamespaceProvider().localStorageArea(*document);
 
     if (!storageArea->canAccessStorage(m_frame)) {
         ec = SECURITY_ERR;
diff --git a/Source/WebCore/page/Navigator.cpp b/Source/WebCore/page/Navigator.cpp
index bb2a254cac88..25895bf54154 100644
--- a/Source/WebCore/page/Navigator.cpp
+++ b/Source/WebCore/page/Navigator.cpp
@@ -37,7 +37,6 @@
 #include "ScriptController.h"
 #include "SecurityOrigin.h"
 #include "Settings.h"
-#include "StorageNamespace.h"
 #include <wtf/HashSet.h>
 #include <wtf/NumberOfCores.h>
 #include <wtf/StdLibExtras.h>
diff --git a/Source/WebCore/storage/StorageNamespaceProvider.cpp b/Source/WebCore/storage/StorageNamespaceProvider.cpp
index a7844c4e4065..acf373ff1d71 100644
--- a/Source/WebCore/storage/StorageNamespaceProvider.cpp
+++ b/Source/WebCore/storage/StorageNamespaceProvider.cpp
@@ -26,6 +26,8 @@
 #include "config.h"
 #include "StorageNamespaceProvider.h"
 
+#include "Document.h"
+#include "StorageArea.h"
 #include "StorageNamespace.h"
 
 namespace WebCore {
@@ -56,6 +58,13 @@ void StorageNamespaceProvider::removePage(Page& page)
     m_pages.remove(&page);
 }
 
+RefPtr<StorageArea> StorageNamespaceProvider::localStorageArea(Document& document)
+{
+    auto& storageNamespace = document.securityOrigin()->canAccessLocalStorage(document.topOrigin()) ? localStorageNamespace() : transientLocalStorageNamespace(*document.topOrigin());
+
+    return storageNamespace.storageArea(document.securityOrigin());
+}
+
 StorageNamespace& StorageNamespaceProvider::localStorageNamespace()
 {
     if (!m_localStorageNamespace)
diff --git a/Source/WebCore/storage/StorageNamespaceProvider.h b/Source/WebCore/storage/StorageNamespaceProvider.h
index 260ee1086f5c..8391bd4c2e6a 100644
--- a/Source/WebCore/storage/StorageNamespaceProvider.h
+++ b/Source/WebCore/storage/StorageNamespaceProvider.h
@@ -34,8 +34,10 @@
 
 namespace WebCore {
 
+class Document;
 class Page;
 class SecurityOrigin;
+class StorageArea;
 class StorageNamespace;
 
 class StorageNamespaceProvider : public RefCounted<StorageNamespaceProvider> {
@@ -44,8 +46,7 @@ class StorageNamespaceProvider : public RefCounted<StorageNamespaceProvider> {
     virtual ~StorageNamespaceProvider();
 
     virtual RefPtr<StorageNamespace> createSessionStorageNamespace(Page&, unsigned quota) = 0;
-    StorageNamespace& localStorageNamespace();
-    StorageNamespace& transientLocalStorageNamespace(SecurityOrigin&);
+    RefPtr<StorageArea> localStorageArea(Document&);
 
     void addPage(Page&);
     void removePage(Page&);
@@ -54,6 +55,9 @@ class StorageNamespaceProvider : public RefCounted<StorageNamespaceProvider> {
     StorageNamespace* optionalLocalStorageNamespace() { return m_localStorageNamespace.get(); }
 
 private:
+    StorageNamespace& localStorageNamespace();
+    StorageNamespace& transientLocalStorageNamespace(SecurityOrigin&);
+
     virtual RefPtr<StorageNamespace> createLocalStorageNamespace(unsigned quota) = 0;
     virtual RefPtr<StorageNamespace> createTransientLocalStorageNamespace(SecurityOrigin&, unsigned quota) = 0;