Navigation transitions (web to native app): Hide/Show transition elements (Blink side)

Source/web/WebDocument.cpp

Index: Source/web/WebDocument.cpp
diff --git a/Source/web/WebDocument.cpp b/Source/web/WebDocument.cpp
index 9c251ea465a13790de4831de7dabccd4c2e4663d..9827819fc4c8b222ad9441a60d312145fb1c05dd 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -296,6 +296,18 @@ void WebDocument::beginExitTransition(const WebString& cssSelector)
     document->styleEngine()->enableExitTransitionStylesheets();
 }
 
+void WebDocument::hideTransitionElements(const WebString& cssSelector)
+{
+    RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
+    document->hideTransitionElements(cssSelector);
+}
+
+void WebDocument::showTransitionElements(const WebString& cssSelector)
+{
+    RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
+    document->hideTransitionElements(cssSelector);
+}
+
 WebAXObject WebDocument::accessibilityObject() const
 {
     const Document* document = constUnwrap<Document>();