Autofill: Set requirements for number of recognized fields in an autofillable form

components/autofill/content/renderer/form_cache.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_
 #define COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_
 
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 16 matching lines @@
 struct FormDataPredictions;
 
 // Manages the forms in a single RenderFrame.
 class FormCache {
  public:
   explicit FormCache(const blink::WebFrame& frame);
   ~FormCache();
 
   // Scans the DOM in |frame_| extracting and storing forms that have not been
   // seen before. Returns the extracted forms.
-  std::vector<FormData> ExtractNewForms();
+  // Writes the index of the unowned form to |unowned_form_index|, or the size
+  // of the returned vector if no unowned form exists.
+  std::vector<FormData> ExtractNewForms(size_t* unowned_form_index);
 
   // Resets the forms.
   void Reset();
 
   // Clears the values of all input elements in the form that contains
   // |element|.  Returns false if the form is not found.
   bool ClearFormWithElement(const blink::WebFormControlElement& element);
 
   // For each field in the |form|, sets the field's placeholder text to the
   // field's overall predicted type.  Also sets the title to include the field's
@@ skipping 26 matching lines @@
 
   // The cached initial values for checkable <input> elements.
   std::map<const blink::WebInputElement, bool> initial_checked_state_;
 
   DISALLOW_COPY_AND_ASSIGN(FormCache);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_