Have Node::document() return a reference instead of a pointer

Source/core/editing/Editor.cpp

Index: Source/core/editing/Editor.cpp
diff --git a/Source/core/editing/Editor.cpp b/Source/core/editing/Editor.cpp
index b487c8d243b83d1b95f90431143bcee82be08428..8ba1b9eccb5fcf34505ef931acf1508f7a66efd2 100644
--- a/Source/core/editing/Editor.cpp
+++ b/Source/core/editing/Editor.cpp
@@ -838,7 +838,7 @@ bool Editor::insertTextWithoutSendingTextEvent(const String& text, bool selectIn
     selection = selectionForCommand(triggeringEvent);
     if (selection.isContentEditable()) {
         if (Node* selectionStart = selection.start().deprecatedNode()) {
-            RefPtr<Document> document = selectionStart->document();
+            RefPtr<Document> document = &selectionStart->document();
 
             // Insert the text
             TypingCommand::Options options = 0;
@@ -981,7 +981,7 @@ void Editor::simplifyMarkup(Node* startNode, Node* endNode)
     if (!startNode)
         return;
     if (endNode) {
-        if (startNode->document() != endNode->document())
+        if (&startNode->document() != &endNode->document())
             return;
         // check if start node is before endNode
         Node* node = startNode;
@@ -1602,7 +1602,7 @@ void Editor::markAndReplaceFor(PassRefPtr<SpellCheckRequest> request, const Vect
         if (shouldMarkSpelling && result->type == TextCheckingTypeSpelling && resultLocation >= paragraph.checkingStart() && resultLocation + resultLength <= spellingRangeEndOffset && !resultEndsAtAmbiguousBoundary) {
             ASSERT(resultLength > 0 && resultLocation >= 0);
             RefPtr<Range> misspellingRange = paragraph.subrange(resultLocation, resultLength);
-            misspellingRange->startContainer()->document()->markers()->addMarker(misspellingRange.get(), DocumentMarker::Spelling, result->replacement, result->hash);
+            misspellingRange->startContainer()->document().markers()->addMarker(misspellingRange.get(), DocumentMarker::Spelling, result->replacement, result->hash);
         } else if (shouldMarkGrammar && result->type == TextCheckingTypeGrammar && paragraph.checkingRangeCovers(resultLocation, resultLength)) {
             ASSERT(resultLength > 0 && resultLocation >= 0);
             for (unsigned j = 0; j < result->details.size(); j++) {
@@ -1610,7 +1610,7 @@ void Editor::markAndReplaceFor(PassRefPtr<SpellCheckRequest> request, const Vect
                 ASSERT(detail->length > 0 && detail->location >= 0);
                 if (paragraph.checkingRangeCovers(resultLocation + detail->location, detail->length)) {
                     RefPtr<Range> badGrammarRange = paragraph.subrange(resultLocation + detail->location, detail->length);
-                    badGrammarRange->startContainer()->document()->markers()->addMarker(badGrammarRange.get(), DocumentMarker::Grammar, detail->userDescription, result->hash);
+                    badGrammarRange->startContainer()->document().markers()->addMarker(badGrammarRange.get(), DocumentMarker::Grammar, detail->userDescription, result->hash);
                 }
             }
         }