Improve autofill form matching.

components/autofill/core/browser/autofill_manager.h

Index: components/autofill/core/browser/autofill_manager.h
diff --git a/components/autofill/core/browser/autofill_manager.h b/components/autofill/core/browser/autofill_manager.h
index ef345081537bae81fdf59b20849507f7f8137dcb..0d6617fd8f34ac439783a94db496044906cb1893 100644
--- a/components/autofill/core/browser/autofill_manager.h
+++ b/components/autofill/core/browser/autofill_manager.h
@@ -412,6 +412,13 @@ class AutofillManager : public AutofillDownloadManager::Observer,
   // Parses the forms using heuristic matching and querying the Autofill server.
   void ParseForms(const std::vector<FormData>& forms);
 
+  // Parses the form and adds it to |form_structures_|. If
+  // |check_for_duplicates| is set, the form will not be added if it's already
+  // exist in |form_structures_|.
+  bool ParseForm(const FormData& form,
+                 const bool check_for_duplicates,
+                 FormStructure** parsed_form_structure);
+
   // Imports the form data, submitted by the user, into |personal_data_|.
   void ImportFormData(const FormStructure& submitted_form);