Move usage of WebString methods into renderer for FrameOwnerProperties

content/common/frame_owner_properties.h

Index: content/common/frame_owner_properties.h
diff --git a/content/common/frame_owner_properties.h b/content/common/frame_owner_properties.h
index b41b3a7180d6274d8ea2cda2d1097e3837012f5b..7773d406f640e144d0946bff3367e1bb4505edde 100644
--- a/content/common/frame_owner_properties.h
+++ b/content/common/frame_owner_properties.h
@@ -19,12 +19,8 @@ namespace content {
 struct CONTENT_EXPORT FrameOwnerProperties {
   FrameOwnerProperties();
   FrameOwnerProperties(const FrameOwnerProperties& other);
-  explicit FrameOwnerProperties(
-      const blink::WebFrameOwnerProperties& web_frame_owner_properties);
   ~FrameOwnerProperties();
 
-  blink::WebFrameOwnerProperties ToWebFrameOwnerProperties() const;
-
   bool operator==(const FrameOwnerProperties& other) const;
   bool operator!=(const FrameOwnerProperties& other) const {
     return !(*this == other);