Expose InlineTextBoxes in the accessibility tree.

Source/core/accessibility/AccessibilityObject.h

Index: Source/core/accessibility/AccessibilityObject.h
diff --git a/Source/core/accessibility/AccessibilityObject.h b/Source/core/accessibility/AccessibilityObject.h
index 72bc24e5d8fff84105dda1a48fb9b7e3115f7f34..e91afdda5c9a30342b2ec805095997dd1f8088f0 100644
--- a/Source/core/accessibility/AccessibilityObject.h
+++ b/Source/core/accessibility/AccessibilityObject.h
@@ -101,6 +101,7 @@ enum AccessibilityRole {
     ImageMapRole,
     ImageRole,
     IncrementorRole,
+    InlineTextBoxRole,
     LabelRole,
     LegendRole,
     LinkRole,
@@ -409,6 +410,12 @@ public:
     virtual AccessibilityObject* titleUIElement() const { return 0; }
     virtual KURL url() const { return KURL(); }
 
+    // For an inline text box.
+    // The integer horizontal pixel offset of each character in the string; negative values for RTL.
+    virtual void textCharacterOffsets(Vector<int>&) const { }
+    // The start and end character offset of each word in the inline text box.
+    virtual void wordBoundaries(Vector<int>& starts, Vector<int>& ends) const { }
+
     // Properties of interactive elements.
     virtual String actionVerb() const;
     virtual AccessibilityButtonState checkboxOrRadioValue() const;