Cleanup: Remove some unused code, or make them platform specific.

chrome/browser/autocomplete/autocomplete_controller.h

Index: chrome/browser/autocomplete/autocomplete_controller.h
===================================================================
--- chrome/browser/autocomplete/autocomplete_controller.h	(revision 246675)
+++ chrome/browser/autocomplete/autocomplete_controller.h	(working copy)
@@ -45,9 +45,6 @@
 // matches from a series of providers into one AutocompleteResult.
 class AutocompleteController : public AutocompleteProviderListener {
  public:
-  // Used to indicate an index that is not selected in a call to Update().
-  static const int kNoItemSelected;
-
   // |provider_types| is a bitmap containing AutocompleteProvider::Type values
   // that will (potentially, depending on platform, flags, etc.) be
   // instantiated.