Navigation transitions (web to native app): Revert exit transition (Blink side)

Source/web/WebDocument.cpp

Index: Source/web/WebDocument.cpp
diff --git a/Source/web/WebDocument.cpp b/Source/web/WebDocument.cpp
index 8b08916e4c63b1606ac21bed974b04da4b63ee39..dca02c15e2ec5872839da69f5c331ab21d05d83f 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -284,10 +284,19 @@ WebSize WebDocument::maximumScrollOffset() const
     return WebSize();
 }
 
+// FIXME: This will be removed once Chrome side implementation is done.
 void WebDocument::setIsTransitionDocument()
 {
     // This ensures the transition UA stylesheet gets applied.
-    unwrap<Document>()->setIsTransitionDocument();
+    unwrap<Document>()->setIsTransitionDocument(true);
+}
+
+void WebDocument::setIsTransitionDocument(bool isTransitionDocument)
+{
+    // When isTransitionDocument is true, it ensures the transition UA
+    // stylesheet gets applied. When isTransitionDocument is false, it ensures
+    // the transition UA stylesheet is not applied when reverting the transition.
+    unwrap<Document>()->setIsTransitionDocument(isTransitionDocument);
 }
 
 void WebDocument::beginExitTransition(const WebString& cssSelector, bool exitToNativeApp)
@@ -295,7 +304,13 @@ void WebDocument::beginExitTransition(const WebString& cssSelector, bool exitToN
     RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
     if (!exitToNativeApp)
         document->hideTransitionElements(cssSelector);
-    document->styleEngine()->enableExitTransitionStylesheets();
+    document->styleEngine()->setExitTransitionStylesheetsEnabled(true);
+}
+
+void WebDocument::revertExitTransition()
+{
+    RefPtrWillBeRawPtr<Document> document = unwrap<Document>();
+    document->styleEngine()->setExitTransitionStylesheetsEnabled(false);
 }
 
 void WebDocument::hideTransitionElements(const WebString& cssSelector)