Expose InlineTextBoxes in the accessibility tree.

public/web/WebAccessibilityObject.h

Index: public/web/WebAccessibilityObject.h
diff --git a/public/web/WebAccessibilityObject.h b/public/web/WebAccessibilityObject.h
index ac0bb1e1a1d1766b5935a69855a3d6c3bcfbe7e1..01a5b57d5fa55a7d87ac0b9a6d361bb0006d8307 100644
--- a/public/web/WebAccessibilityObject.h
+++ b/public/web/WebAccessibilityObject.h
@@ -78,6 +78,9 @@ public:
     WEBKIT_EXPORT static void enableAccessibility();
     WEBKIT_EXPORT static bool accessibilityEnabled();
 
+    // Temporary: this flag will only be toggleable until Chromium has it on by default.
+    WEBKIT_EXPORT static void enableInlineTextBoxAccessibility();
+
     WEBKIT_EXPORT void startCachingComputedObjectAttributesUntilTreeMutates();
     WEBKIT_EXPORT void stopCachingComputedObjectAttributes();
 
@@ -198,6 +201,10 @@ public:
     WEBKIT_EXPORT unsigned cellRowIndex() const;
     WEBKIT_EXPORT unsigned cellRowSpan() const;
 
+    // For an inline text box.
+    WEBKIT_EXPORT void characterOffsets(WebVector<int>&) const;
+    WEBKIT_EXPORT void wordBoundaries(WebVector<int>& starts, WebVector<int>& ends) const;
+
     // Make this object visible by scrolling as many nested scrollable views as needed.
     WEBKIT_EXPORT void scrollToMakeVisible() const;
     // Same, but if the whole object can't be made visible, try for this subrect, in local coordinates.