Introduce Position::inDocument()

Source/core/editing/ApplyStyleCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008, 2009 Apple Inc. 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1049 matching lines @@
             if (child == targetNode || child->contains(targetNode))
                 current = child;
         }
     }
 }
 
 void ApplyStyleCommand::removeInlineStyle(EditingStyle* style, const Position &start, const Position &end)
 {
     ASSERT(start.isNotNull());
     ASSERT(end.isNotNull());
-    ASSERT(start.anchorNode()->inDocument());
-    ASSERT(end.anchorNode()->inDocument());
+    ASSERT(start.inDocument());
+    ASSERT(end.inDocument());
     ASSERT(comparePositions(start, end) <= 0);
     // FIXME: We should assert that start/end are not in the middle of a text node.
 
     Position pushDownStart = start.downstream();
     // If the pushDownStart is at the end of a text node, then this node is not fully selected.
     // Move it to the next deep quivalent position to avoid removing the style from this node.
     // e.g. if pushDownStart was at Position("hello", 5) in <b>hello<div>world</div></b>, we want Position("world", 0) instead.
     Node* pushDownStartContainer = pushDownStart.containerNode();
     if (pushDownStartContainer && pushDownStartContainer->isTextNode()
         && pushDownStart.computeOffsetInContainerNode() == pushDownStartContainer->maxCharacterOffset())
@@ skipping 459 matching lines @@
         String textToMove = nextText->data();
         insertTextIntoNode(childText, childText->length(), textToMove);
         removeNode(next);
         // don't move child node pointer. it may want to merge with more text nodes.
     }
 
     updateStartEnd(newStart, newEnd);
 }
 
 }