[Autofill] Fill from the last digits when filling a phone number with a maximum length.

components/autofill/core/browser/autofill_field.h

Index: components/autofill/core/browser/autofill_field.h
diff --git a/components/autofill/core/browser/autofill_field.h b/components/autofill/core/browser/autofill_field.h
index 8295440e822399546488b52305ac3e893819de29..d869ab86c536f17632f2477d4ca82d82d62fddda 100644
--- a/components/autofill/core/browser/autofill_field.h
+++ b/components/autofill/core/browser/autofill_field.h
@@ -93,8 +93,8 @@ class AutofillField : public FormFieldData {
                             FormFieldData* field_data);
 
   // Returns the phone number value for the given |field|. The returned value
-  // might be |number|, or could possibly be a prefix or suffix of |number|
-  // if that's appropriate for the field.
+  // might be |number|, or could possibly be a meaningful subset |number|, if
+  // that's appropriate for the field.
   static base::string16 GetPhoneNumberValue(const AutofillField& field,
                                             const base::string16& number,
                                             const FormFieldData& field_data);