Select/deselect and isIndexSelected for Comboboxes and Listboxes.

Part of feature work to make Pdfium more usable by mobile platforms
that wish to render comboboxes and listboxes using custom displays
when a widget is selected instead of Pdfium's support for drawing
the dropdown/selected items.

R=thestig@chromium.org

Bug: b/124253371
Change-Id: Idd1759bd7a7ab2ae518583e9325dfd094d91c8ad
Reviewed-on: https://pdfium-review.googlesource.com/c/50650
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fpdfsdk/cpdfsdk_annothandlermgr.cpp b/fpdfsdk/cpdfsdk_annothandlermgr.cpp
index 619d66d..0061eb5 100644
--- a/fpdfsdk/cpdfsdk_annothandlermgr.cpp
+++ b/fpdfsdk/cpdfsdk_annothandlermgr.cpp
@@ -255,6 +255,20 @@
   return GetAnnotHandler(pAnnot->Get())->OnKillFocus(pAnnot, nFlag);
 }
 
+bool CPDFSDK_AnnotHandlerMgr::Annot_SetIndexSelected(
+    CPDFSDK_Annot::ObservedPtr* pAnnot,
+    int index,
+    bool selected) {
+  return GetAnnotHandler(pAnnot->Get())
+      ->SetIndexSelected(pAnnot, index, selected);
+}
+
+bool CPDFSDK_AnnotHandlerMgr::Annot_IsIndexSelected(
+    CPDFSDK_Annot::ObservedPtr* pAnnot,
+    int index) {
+  return GetAnnotHandler(pAnnot->Get())->IsIndexSelected(pAnnot, index);
+}
+
 #ifdef PDF_ENABLE_XFA
 bool CPDFSDK_AnnotHandlerMgr::Annot_OnChangeFocus(
     CPDFSDK_Annot::ObservedPtr* pSetAnnot,