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

components/autofill/core/browser/personal_data_manager.cc

Index: components/autofill/core/browser/personal_data_manager.cc
diff --git a/components/autofill/core/browser/personal_data_manager.cc b/components/autofill/core/browser/personal_data_manager.cc
index 5d234adfaac692e3be272d361ac51b9cef83bd2f..9ee14cbad06ce42cf7cf493b746d63641fa68748 100644
--- a/components/autofill/core/browser/personal_data_manager.cc
+++ b/components/autofill/core/browser/personal_data_manager.cc
@@ -30,6 +30,7 @@
 #include "components/autofill/core/browser/validation.h"
 #include "components/autofill/core/common/autofill_pref_names.h"
 #include "components/autofill/core/common/autofill_switches.h"
+#include "components/autofill/core/common/autofill_util.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "components/signin/core/common/signin_pref_names.h"
 #include "third_party/libaddressinput/src/cpp/include/libaddressinput/address_data.h"
@@ -870,8 +871,8 @@ std::vector<Suggestion> PersonalDataManager::GetProfileSuggestions(
 
       base::string16 value_canon =
           AutofillProfile::CanonicalizeProfileString(values[i]);
-      if (StartsWith(value_canon, field_contents_canon, true)) {
-        // Prefix match, add suggestion.
+      if (StartsWith(value_canon, field_contents_canon, true) ||
+          IsContentsPrefixOfSuggestionToken(values[i], field_contents, false)) {

[Evan Stade, 2015/05/22 18:26:48]

to match the naming format of StartsWith, can you make this
"ContainsTokenThatStartsWith"

also, why do you not use field_contents_canon and value_canon? I don't know if
it's correct or not, but it looks weirdly divergent from the line above, so if
it's correct you should justify it with a comment in the code.

[Pritam Nikam, 2015/05/25 18:14:51]

Done.
If we opt to use field_contents_canon and value_canon in
IsContentsPrefixOfSuggestionToken(), field_contents_canon holds canonicalize
input i.e. text having separators replaced with whitespace, and leads to
unexpected results.
For instance,
values[i]: "test@example.org" -> value_canon: "test example org"
field_contents: "exam...." -> field_contents_canon: "exam"

This 'll pass IsContentsPrefixOfSuggestionToken() and will bring
"test@example.org" in suggestions list, which seems wrong.

         matched_profiles.push_back(profile);
         suggestions.push_back(Suggestion(values[i]));
         suggestions.back().backend_id.guid = profile->guid();
@@ -946,7 +947,9 @@ std::vector<Suggestion> PersonalDataManager::GetCreditCardSuggestions(
            field_contents.size() >= 6)) {
         continue;
       }
-    } else if (!StartsWith(creditcard_field_value, field_contents, false)) {
+    } else if (!StartsWith(creditcard_field_value, field_contents, false) &&
+               !IsContentsPrefixOfSuggestionToken(creditcard_field_value,
+                                                  field_contents, false)) {
       continue;
     }