Make first-letter style to work with editing

Source/core/editing/VisibleUnits.cpp

Index: Source/core/editing/VisibleUnits.cpp
diff --git a/Source/core/editing/VisibleUnits.cpp b/Source/core/editing/VisibleUnits.cpp
index 92f8be86c7e01c6486f836bde5dd0dff359000a6..6b4e0fabe301218dd0a831a86c15c7f6cc5d9351 100644
--- a/Source/core/editing/VisibleUnits.cpp
+++ b/Source/core/editing/VisibleUnits.cpp
@@ -1134,16 +1134,16 @@ VisiblePosition startOfParagraph(const VisiblePosition& c, EditingBoundaryCrossi
 
         if (r->isText() && toRenderText(r)->renderedTextLength()) {
             ASSERT_WITH_SECURITY_IMPLICATION(n->isTextNode());
+            RenderText* text = toRenderText(r);
             type = Position::PositionIsOffsetInAnchor;
             if (style->preserveNewline()) {
-                RenderText* text = toRenderText(r);
                 int i = text->textLength();
                 int o = offset;
                 if (n == startNode && o < i)
                     i = max(0, o);
                 while (--i >= 0) {
                     if ((*text)[i] == '\n')
-                        return VisiblePosition(Position(toText(n), i + 1), DOWNSTREAM);
+                        return VisiblePosition(Position(toText(n), i + text->textStartOffset() + 1), DOWNSTREAM);
                 }
             }
             node = n;
@@ -1212,18 +1212,18 @@ VisiblePosition endOfParagraph(const VisiblePosition &c, EditingBoundaryCrossing
         // FIXME: We avoid returning a position where the renderer can't accept the caret.
         if (r->isText() && toRenderText(r)->renderedTextLength()) {
             ASSERT_WITH_SECURITY_IMPLICATION(n->isTextNode());
-            int length = toRenderText(r)->textLength();
+            RenderText* text = toRenderText(r);
+            int length = text->textLength();
             type = Position::PositionIsOffsetInAnchor;
             if (style->preserveNewline()) {
-                RenderText* text = toRenderText(r);
                 int o = n == startNode ? offset : 0;
                 for (int i = o; i < length; ++i) {
                     if ((*text)[i] == '\n')
-                        return VisiblePosition(Position(toText(n), i), DOWNSTREAM);
+                        return VisiblePosition(Position(toText(n), i + text->textStartOffset()), DOWNSTREAM);
                 }
             }
             node = n;
-            offset = r->caretMaxOffset();
+            offset = r->caretMaxOffset() + text->textStartOffset();
             n = NodeTraversal::next(n, stayInsideBlock);
         } else if (editingIgnoresContent(n) || isTableElement(n)) {
             node = n;