Use |FrameSelection::selectedText()| where possible.

third_party/WebKit/Source/core/editing/serializers/Serialization.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 225 matching lines @@
 public:
     static String createMarkup(const PositionTemplate<Strategy>& startPosition, const PositionTemplate<Strategy>& endPosition, EAnnotateForInterchange shouldAnnotate = DoNotAnnotateForInterchange, ConvertBlocksToInlines = ConvertBlocksToInlines::NotConvert, EAbsoluteURLs shouldResolveURLs = DoNotResolveURLs, Node* constrainingAncestor = nullptr);
 };
 
 // FIXME: Shouldn't we omit style info when annotate == DoNotAnnotateForInterchange?
 // FIXME: At least, annotation and style info should probably not be included in range.markupString()
 template <typename Strategy>
 String CreateMarkupAlgorithm<Strategy>::createMarkup(const PositionTemplate<Strategy>& startPosition, const PositionTemplate<Strategy>& endPosition,
     EAnnotateForInterchange shouldAnnotate, ConvertBlocksToInlines convertBlocksToInlines, EAbsoluteURLs shouldResolveURLs, Node* constrainingAncestor)
 {
-    ASSERT(startPosition.isNotNull());
-    ASSERT(endPosition.isNotNull());
+    if (startPosition.isNull() || endPosition.isNull())
+        return emptyString();
+
     ASSERT(startPosition.compareTo(endPosition) <= 0);
 
     bool collapsed = startPosition == endPosition;
     if (collapsed)
         return emptyString();
     Node* commonAncestor = Strategy::commonAncestor(*startPosition.computeContainerNode(), *endPosition.computeContainerNode());
     if (!commonAncestor)
         return emptyString();
 
     Document* document = startPosition.document();
     document->updateLayoutIgnorePendingStylesheets();
 
     HTMLElement* specialCommonAncestor = highestAncestorToWrapMarkup<Strategy>(startPosition, endPosition, shouldAnnotate, constrainingAncestor);
     StyledMarkupSerializer<Strategy> serializer(shouldResolveURLs, shouldAnnotate, startPosition, endPosition, specialCommonAncestor, convertBlocksToInlines);
     return serializer.createMarkup();
 }
 
 String createMarkup(const Position& startPosition, const Position& endPosition, EAnnotateForInterchange shouldAnnotate, ConvertBlocksToInlines convertBlocksToInlines, EAbsoluteURLs shouldResolveURLs, Node* constrainingAncestor)
 {
-    ASSERT(startPosition.compareTo(endPosition) <= 0);
     return CreateMarkupAlgorithm<EditingStrategy>::createMarkup(startPosition, endPosition, shouldAnnotate, convertBlocksToInlines, shouldResolveURLs, constrainingAncestor);
 }
 
 String createMarkup(const PositionInComposedTree& startPosition, const PositionInComposedTree& endPosition, EAnnotateForInterchange shouldAnnotate, ConvertBlocksToInlines convertBlocksToInlines, EAbsoluteURLs shouldResolveURLs, Node* constrainingAncestor)
 {
-    ASSERT(startPosition.compareTo(endPosition) <= 0);
     return CreateMarkupAlgorithm<EditingInComposedTreeStrategy>::createMarkup(startPosition, endPosition, shouldAnnotate, convertBlocksToInlines, shouldResolveURLs, constrainingAncestor);
 }
 
 PassRefPtrWillBeRawPtr<DocumentFragment> createFragmentFromMarkup(Document& document, const String& markup, const String& baseURL, ParserContentPolicy parserContentPolicy)
 {
     // We use a fake body element here to trick the HTML parser to using the InBody insertion mode.
     RefPtrWillBeRawPtr<HTMLBodyElement> fakeBody = HTMLBodyElement::create(document);
     RefPtrWillBeRawPtr<DocumentFragment> fragment = DocumentFragment::create(document);
 
     fragment->parseHTML(markup, fakeBody.get(), parserContentPolicy);
@@ skipping 416 matching lines @@
     RefPtrWillBeRawPtr<Text> textNext = toText(next);
     textNode->appendData(textNext->data());
     if (textNext->parentNode()) // Might have been removed by mutation event.
         textNext->remove(exceptionState);
 }
 
 template class CORE_TEMPLATE_EXPORT CreateMarkupAlgorithm<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT CreateMarkupAlgorithm<EditingInComposedTreeStrategy>;
 
 }