Add observer for BAAnnots from Javascript

fpdfsdk/javascript/Field.cpp

Index: fpdfsdk/javascript/Field.cpp
diff --git a/fpdfsdk/javascript/Field.cpp b/fpdfsdk/javascript/Field.cpp
index 5c279d6b53a9839a077efca1d18e66f045f9b531..3209efc6e8976e29f24f05473e4511f436a6745e 100644
--- a/fpdfsdk/javascript/Field.cpp
+++ b/fpdfsdk/javascript/Field.cpp
@@ -267,9 +267,10 @@ void Field::UpdateFormField(CPDFSDK_Document* pDocument,
   if (bResetAP) {
     int nFieldType = pFormField->GetFieldType();
     if (nFieldType == FIELDTYPE_COMBOBOX || nFieldType == FIELDTYPE_TEXTFIELD) {
-      for (CPDFSDK_Widget* pWidget : widgets) {
+      for (CPDFSDK_Annot* pAnnot : widgets) {
         FX_BOOL bFormatted = FALSE;
-        CPDFSDK_Widget::Observer observer(&pWidget);
+        CPDFSDK_Widget* pWidget = static_cast<CPDFSDK_Widget*>(pAnnot);
+        CPDFSDK_Widget::Observer observer(&pAnnot);
         CFX_WideString sValue = pWidget->OnFormat(bFormatted);
         if (pWidget) {

[Tom Sepez, 2016/09/01 20:06:23]

Need to check pannot here, its the thing that gets cleared.  Also, if the loop
is in terms of widgets, you can just assign to the pAnnot* without casting.

[dsinclair, 2016/09/06 15:44:49]

Done.

Not sure what you're referring to about the casting. The static_cast on 272 is
needed otherwise the compiler complains.

cannot initialize a variable of type 'CPDFSDK_Widget *' with an lvalue of type
'CPDFSDK_Annot *'

           pWidget->ResetAppearance(bFormatted ? sValue.c_str() : nullptr,