diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 25dc7c7d9523..03269dc26de6 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -365,6 +365,7 @@
 #include "nsStreamUtils.h"
 #include "nsString.h"
 #include "nsStringBuffer.h"
+#include "nsStringBundle.h"
 #include "nsStringFlags.h"
 #include "nsStringFwd.h"
 #include "nsStringIterator.h"
@@ -4084,6 +4085,16 @@ static const char* gPropertiesFiles[nsContentUtils::PropertiesFile_COUNT] = {
     "resource://gre/res/locale/layout/HtmlForm.properties",
     "resource://gre/res/locale/dom/dom.properties"};
 
+/* static */
+nsresult nsContentUtils::EnsureAndLoadStringBundle(PropertiesFile aFile) {
+  MOZ_ASSERT(NS_IsMainThread(), "Should be called on main thread.");
+  nsresult rv = EnsureStringBundle(aFile);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  return nsStringBundleBase::Cast(sStringBundles[aFile])->LoadProperties();
+}
+
 /* static */
 nsresult nsContentUtils::EnsureStringBundle(PropertiesFile aFile) {
   if (!sStringBundles[aFile]) {
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index 4a7bc62fe746..32e94c16437b 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -3358,6 +3358,13 @@ class nsContentUtils {
    */
   static uint32_t ResolveObjectType(uint32_t aType);
 
+  /**
+   * Create and load the string bundle for the 'aFile'.
+   * This API is used to preload the string bundle on the main thread so later
+   * other thread could access it.
+   */
+  static nsresult EnsureAndLoadStringBundle(PropertiesFile aFile);
+
  private:
   static bool InitializeEventTable();
 
diff --git a/intl/strres/moz.build b/intl/strres/moz.build
index 564d3d690ea8..0146366cdeb8 100644
--- a/intl/strres/moz.build
+++ b/intl/strres/moz.build
@@ -20,6 +20,10 @@ LOCAL_INCLUDES += [
     "/xpcom/ds",
 ]
 
+EXPORTS += [
+    "nsStringBundle.h",
+]
+
 include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"