Hide textarea placeholder text when showing autofill suggestion

Source/core/html/HTMLTextAreaElement.h

Index: Source/core/html/HTMLTextAreaElement.h
diff --git a/Source/core/html/HTMLTextAreaElement.h b/Source/core/html/HTMLTextAreaElement.h
index f33274c029a86b72eff36a8659691b09631c82c2..63ef906fa9d1232153d08954538e686e179245d0 100644
--- a/Source/core/html/HTMLTextAreaElement.h
+++ b/Source/core/html/HTMLTextAreaElement.h
@@ -81,6 +81,7 @@ private:
     virtual bool supportsPlaceholder() const OVERRIDE { return true; }
     virtual void updatePlaceholderText() OVERRIDE;
     virtual bool isEmptyValue() const OVERRIDE { return value().isEmpty(); }
+    virtual bool isEmptySuggestedValue() const OVERRIDE FINAL { return suggestedValue().isEmpty(); }
 
     virtual bool isOptionalFormControl() const OVERRIDE { return !isRequiredFormControl(); }
     virtual bool isRequiredFormControl() const OVERRIDE { return isRequired(); }