[Autofill/Autocomplete Feature] Substring matching instead of prefix matching.

components/autofill/core/common/autofill_util.h

Index: components/autofill/core/common/autofill_util.h
diff --git a/components/autofill/core/common/autofill_util.h b/components/autofill/core/common/autofill_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..51649b3a43fecf2ec0486229251f56a8f42ba89b
--- /dev/null
+++ b/components/autofill/core/common/autofill_util.h
@@ -0,0 +1,33 @@
+// Copyright 2015 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_COMMON_AUTOFILL_UTIL_H_
+#define COMPONENTS_AUTOFILL_CORE_COMMON_AUTOFILL_UTIL_H_
+
+#include "base/strings/string16.h"
+
+namespace autofill {
+
+// Returns |true| when command line switch
+// |kEnableSuggestionsWithSubstringMatch| is on; otherwise |false|.
+bool IsFeatureSubstringMatchEnabled();
+
+// Splits |field_suggestion| into tokens, separated by characters from " .,-_@".
+// Returns true if command line switch |kEnableSuggestionsWithSubstringMatch| is
+// on and |field_content| is a prefix of some token; otherwise false.
+bool IsContentsPrefixOfSuggestionToken(const base::string16& field_suggestion,

[Evan Stade, 2015/04/23 20:21:18]

nit: s/field_suggestion/suggestion

[Pritam Nikam, 2015/04/27 07:53:41]

Done.

+                                       const base::string16& field_contents,
+                                       bool case_sensitive);
+
+// Returns |field_contents|'s offset within the |field_suggestion| on successful
+// match and compute the selection range's |start| and |end| indices; otherwise
+// returns |base::string16::npos|.

[Evan Stade, 2015/04/23 20:21:18]

can you work on making this comment clearer? What is the "selection range"?

[Pritam Nikam, 2015/04/27 07:53:41]

Done.

+size_t ComputeRange(const base::string16& field_suggestion,
+                    const base::string16& field_contents,
+                    size_t* start,
+                    size_t* end);
+
+}  // namespace autofill
+
+#endif  // COMPONENTS_AUTOFILL_CORE_COMMON_AUTOFILL_UTIL_H_