Pass null WebString for empty WebSecurityOrigin::suborigin()

third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp

Index: third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp
diff --git a/third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp b/third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp
index bfaaaa10765d49ab2d75ac610a6251ff9daac29b..a23adf0149bedebce379a8f701fb98bea03805ec 100644
--- a/third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp
+++ b/third_party/WebKit/Source/platform/exported/WebSecurityOrigin.cpp
@@ -95,7 +95,8 @@ unsigned short WebSecurityOrigin::effectivePort() const {
 
 WebString WebSecurityOrigin::suborigin() const {
   DCHECK(m_private);
-  return m_private->hasSuborigin() ? m_private->suborigin()->name() : "";
+  return m_private->hasSuborigin() ? WebString(m_private->suborigin()->name())
+                                   : WebString();
 }
 
 bool WebSecurityOrigin::isUnique() const {