[Autofill] Remove longest common prefix from field names when running heuristics.

components/autofill/core/browser/form_structure.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_CORE_BROWSER_FORM_STRUCTURE_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_FORM_STRUCTURE_H_
 
 #include <stddef.h>
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
 #include "components/autofill/core/browser/autofill_field.h"
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/field_types.h"
 #include "components/autofill/core/browser/proto/server.pb.h"
 #include "url/gurl.h"
 
 class XmlWriter;
 
 enum UploadRequired {
   UPLOAD_NOT_REQUIRED,
@@ skipping 178 matching lines @@
 
   // Returns a FormData containing the data this form structure knows about.
   FormData ToFormData() const;
 
   bool operator==(const FormData& form) const;
   bool operator!=(const FormData& form) const;
 
  private:
   friend class FormStructureTest;
   FRIEND_TEST_ALL_PREFIXES(AutofillDownloadTest, QueryAndUploadTest);
+  FRIEND_TEST_ALL_PREFIXES(FormStructureTest, FindLongestCommonPrefix);
 
   // Encodes information about this form and its fields into |query_form|.
   void EncodeFormForQuery(
       autofill::AutofillQueryContents::Form* query_form) const;
 
   // Encodes information about this form and its fields into |upload|.
   void EncodeFormForUpload(autofill::AutofillUploadContents* upload) const;
 
   // 64-bit hash of the string - used in FormSignature and unit-tests.
   static uint64_t Hash64Bit(const std::string& str);
 
   uint64_t FormSignature64Bit() const;
 
   // Returns true if the form has no fields, or too many.
   bool IsMalformed() const;
 
   // Classifies each field in |fields_| into a logical section.
   // Sections are identified by the heuristic that a logical section should not
   // include multiple fields of the same autofill type (with some exceptions, as
   // described in the implementation).  Sections are furthermore distinguished
   // as either credit card or non-credit card sections.
   // If |has_author_specified_sections| is true, only the second pass --
   // distinguishing credit card sections from non-credit card ones -- is made.
   void IdentifySections(bool has_author_specified_sections);
 
   // Returns true if field should be skipped when talking to Autofill server.
   bool ShouldSkipField(const FormFieldData& field) const;
 
+  // Further processes the extracted |fields_|.
+  void ProcessExtractedFields();
+
+  // Returns the longest common prefix found within |strings|. IMPORTANT: the
+  // returned StringPiece16 is a view into |strings| and the latter must remain
+  // valid while the StringPiece16 is used.
+  static base::StringPiece16 FindLongestCommonPrefix(
+      const std::vector<base::string16>& strings);
+
   // The name of the form.
   base::string16 form_name_;
 
   // The source URL.
   GURL source_url_;
 
   // The target URL.
   GURL target_url_;
 
   // The number of fields able to be auto-filled.
@@ skipping 33 matching lines @@
 
   // True if the form is a <form>.
   bool is_form_tag_;
 
   DISALLOW_COPY_AND_ASSIGN(FormStructure);
 };
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_FORM_STRUCTURE_H_