Make first-letter style to work with editing

Source/core/editing/VisiblePosition.cpp

Index: Source/core/editing/VisiblePosition.cpp
diff --git a/Source/core/editing/VisiblePosition.cpp b/Source/core/editing/VisiblePosition.cpp
index e8635680c5efedba69ff8650128238e2029362de..b15441f85b9df4873c9a00fbee9e997f2d808677 100644
--- a/Source/core/editing/VisiblePosition.cpp
+++ b/Source/core/editing/VisiblePosition.cpp
@@ -38,6 +38,7 @@
 #include "core/html/HTMLHtmlElement.h"
 #include "core/platform/graphics/FloatQuad.h"
 #include "core/rendering/RenderBlock.h"
+#include "core/rendering/RenderText.h"
 #include "core/rendering/RootInlineBox.h"
 #include "wtf/text/CString.h"
 
@@ -259,6 +260,8 @@ Position VisiblePosition::leftVisuallyDistinctCandidate() const
             break;
         }
 
+        if (renderer->isText())
+            offset += toRenderText(renderer)->textStartOffset();
         p = createLegacyEditingPosition(renderer->node(), offset);
 
         if ((p.isCandidate() && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
@@ -427,6 +430,8 @@ Position VisiblePosition::rightVisuallyDistinctCandidate() const
             break;
         }
 
+        if (renderer->isText())
+            offset += toRenderText(renderer)->textStartOffset();
         p = createLegacyEditingPosition(renderer->node(), offset);
 
         if ((p.isCandidate() && p.downstream() != downstreamStart) || p.atStartOfTree() || p.atEndOfTree())
@@ -654,9 +659,7 @@ LayoutRect VisiblePosition::localCaretRect(RenderObject*& renderer) const
         renderer = 0;
         return IntRect();
     }
-    Node* node = m_deepPosition.anchorNode();
-
-    renderer = node->renderer();
+    renderer = m_deepPosition.rendererOfAnchorNode();
     if (!renderer)
         return LayoutRect();