[Autofill/Autocomplete Feature] Substring matching instead of prefix matching (Blink).

public/web/WebFormControlElement.h

Index: public/web/WebFormControlElement.h
diff --git a/public/web/WebFormControlElement.h b/public/web/WebFormControlElement.h
index 877e59c86d2ca7ed980fbbd9561e7027e303c8de..0339d123ee1a84b701ea7c1891acfc6ce0a626d0 100644
--- a/public/web/WebFormControlElement.h
+++ b/public/web/WebFormControlElement.h
@@ -110,6 +110,12 @@ public:
 
     BLINK_EXPORT WebFormElement form() const;
 
+    // Sets the text selection start offset for the suggested value for element.
+    BLINK_EXPORT void setSuggestedValueStart(int);
+
+    // Returns the text selection start offset for the suggested value for element.
+    BLINK_EXPORT int suggestedValueStart() const;
+
 #if BLINK_IMPLEMENTATION
     WebFormControlElement(const PassRefPtrWillBeRawPtr<HTMLFormControlElement>&);
     WebFormControlElement& operator=(const PassRefPtrWillBeRawPtr<HTMLFormControlElement>&);