Consider text alignment and direction when computing the left offset for horizontal writing modes.

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index 535b0e65bed7b1af4ce85ef9edad5cfba84b16b1..8302d358c4ef9fe89e081bc1b290fd1ee4d7d46b 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -66,6 +66,7 @@ class RenderTable;
 class RenderTheme;
 class RenderView;
 class ResourceLoadPriorityOptimizer;
+class RootInlineBox;
 class TransformState;
 
 struct PaintInfo;
@@ -786,6 +787,11 @@ public:
     // This is typically only relevant when repainting.
     virtual RenderStyle* outlineStyleForRepaint() const { return style(); }
 
+    // Return LEFT, RIGHT, CENTER or JUSTIFY considering text alignment and direction.
+    // If a specific RootInlineBox is specified, it will be used to calculate the direction to be considered,
+    // otherwise the default direction for the associated style will be used.
+    ETextAlign simplifiedTextAlign(const ETextAlign&, const RootInlineBox* = 0) const;
+
     virtual CursorDirective getCursor(const LayoutPoint&, Cursor&) const;
 
     void getTextDecorationColors(unsigned decorations, Color& underline, Color& overline, Color& linethrough, bool quirksMode = false, bool firstlineStyle = false);