rAc - Only show countries we're able to fill in.

components/autofill/core/browser/form_structure.h

Index: components/autofill/core/browser/form_structure.h
diff --git a/components/autofill/core/browser/form_structure.h b/components/autofill/core/browser/form_structure.h
index 578c4131f12f0b5c071db009b0456ebfb2c92b9d..b49ca1c38d61326c92a1276d02c294b4ef120277 100644
--- a/components/autofill/core/browser/form_structure.h
+++ b/components/autofill/core/browser/form_structure.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_FORM_STRUCTURE_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_FORM_STRUCTURE_H_
 
+#include <set>
 #include <string>
 #include <vector>
 
@@ -151,6 +152,14 @@ class FormStructure {
       const base::Callback<base::string16(const AutofillType&)>& get_info,
       const std::string& app_locale);
 
+  // Returns the values that can be filled into the form structure for the
+  // given type. For example, there's no way to fill in a value of "The Moon"
+  // into ADDRESS_HOME_STATE if the form only has a
+  // <select autocomplete="region"> with no "The Moon" option. Returns an
+  // empty set if the form doesn't reference the given type or if all inputs
+  // are accepted (e.g., <input type="text" autocomplete="region">).
+  std::set<base::string16> PossibleValues(ServerFieldType type);

[Ilya Sherman, 2014/03/03 23:55:54]

'ServerFieldType' is a strange choice of type to pass to this method.  You
probably want an AutofillType instead.

[Ilya Sherman, 2014/03/03 23:55:54]

nit: This method name is rather vague.  Perhaps
"GetPossibleValuesForFieldType()" or something like that?

[Ilya Sherman, 2014/03/03 23:55:54]

You are expanding the public API of this class, so please add a unit test for
this method.

[Evan Stade, 2014/03/04 00:11:30]

I started with that, but it makes the call sites more verbose. ServerFieldType
is expressive enough to describe any type we could want to ask this question
about.

[Evan Stade, 2014/03/04 00:11:30]

Do you think it's vague when you see it in the context of the call site?

[Evan Stade, 2014/03/04 00:11:30]

See my other comment on why I think that is a bad idea.

[Ilya Sherman, 2014/03/04 00:53:57]

Yes, I do.  The call site just forwards a bunch of stuff to a constructor, so
the call site is really not very informative at all.  Besides, you're adding a
public method that might be called from other call sites in the future; so even
if the current call site was overwhelmingly clear, that would not mean that
future call sites would be.

[Ilya Sherman, 2014/03/04 00:53:57]

This code lives in a different component from the unittest code that you've
added.  Soon, it will run as part of a completely separate test binary.

If you prefer not to add test coverage to this class, then please move the
implementation of this code into the AutofillDialogController's anonymous
namespace.  In fact, now that I think about it, that's probably a better place
for this code regardless -- there's really no need to drop it into the shared
code.

+
   const AutofillField* field(size_t index) const;
   AutofillField* field(size_t index);
   size_t field_count() const;