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..1874a9618e2ce0bb19b2ade33493f6b61fe274b4 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -292,10 +292,16 @@ void WebDocument::setIsTransitionDocument()
 void WebDocument::beginExitTransition(const WebString& cssSelector)
 {
     RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
-    document->hideTransitionElements(cssSelector);
+    document->updateTransitionElementOpacity(cssSelector, 0.0);
     document->styleEngine()->enableExitTransitionStylesheets();
 }
 
+void WebDocument::updateTransitionElementOpacity(const WebString& cssSelector, double opacity)
+{
+    RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
+    document->updateTransitionElementOpacity(cssSelector, opacity);
+}
+
 WebAXObject WebDocument::accessibilityObject() const
 {
     const Document* document = constUnwrap<Document>();