Refactoring and tests for the highly undertested file_util::CreateOrUpdateShortcutLink() method.

base/win/win_util.cc

Index: base/win/win_util.cc
diff --git a/base/win/win_util.cc b/base/win/win_util.cc
index 55a4c3c334f071a0cfe279559facbea4852900d2..37aae276d171cab66f4754c14ce3ef4ec4ac37e2 100644
--- a/base/win/win_util.cc
+++ b/base/win/win_util.cc
@@ -175,13 +175,17 @@ bool SetAppIdForPropertyStore(IPropertyStore* property_store,
                                         app_id);
 }
 
-bool SetDualModeForPropertyStore(IPropertyStore* property_store) {
+bool SetDualModeForPropertyStore(IPropertyStore* property_store,
+                                 bool is_dual_mode) {
   return SetBooleanValueForPropertyStore(property_store,
                                          PKEY_AppUserModel_DualMode,
-                                         true) &&
+                                         is_dual_mode) &&
+         // TODO (gab): This property no longer exists in the final Win8 release
+         // and should be deleted from all shortcuts as it could interfere with
+         // a future (Win9+) property.
          SetUInt32ValueForPropertyStore(property_store,
                                         PKEY_AppUserModel_DualMode_UK,
-                                        1U);
+                                        is_dual_mode ? 1U : 0U);
 }
 
 static const char16 kAutoRunKeyPath[] =