PPAPI: Make blocking completion callbacks work.

ppapi/thunk/ppb_file_chooser_thunk.cc

Index: ppapi/thunk/ppb_file_chooser_thunk.cc
diff --git a/ppapi/thunk/ppb_file_chooser_thunk.cc b/ppapi/thunk/ppb_file_chooser_thunk.cc
index 083ffb87e9f8a7f9e85207ea51614e65671d9926..2102436ec08500ffee4b6955dd6d749ce9cc7d78 100644
--- a/ppapi/thunk/ppb_file_chooser_thunk.cc
+++ b/ppapi/thunk/ppb_file_chooser_thunk.cc
@@ -38,7 +38,7 @@ int32_t Show0_5(PP_Resource chooser, PP_CompletionCallback callback) {
   EnterResource<PPB_FileChooser_API> enter(chooser, callback, true);
   if (enter.failed())
     return enter.retval();
-  return enter.SetResult(enter.object()->Show0_5(callback));
+  return enter.SetResult(enter.object()->Show0_5(enter.callback()));
 }
 
 PP_Resource GetNextChosenFile0_5(PP_Resource chooser) {
@@ -54,7 +54,7 @@ int32_t Show(PP_Resource chooser,
   EnterResource<PPB_FileChooser_API> enter(chooser, callback, true);
   if (enter.failed())
     return enter.retval();
-  return enter.SetResult(enter.object()->Show(output, callback));
+  return enter.SetResult(enter.object()->Show(output, enter.callback()));
 }
 
 int32_t ShowWithoutUserGesture0_5(PP_Resource chooser,
@@ -65,7 +65,7 @@ int32_t ShowWithoutUserGesture0_5(PP_Resource chooser,
   if (enter.failed())
     return enter.retval();
   return enter.SetResult(enter.object()->ShowWithoutUserGesture0_5(
-      save_as, suggested_file_name, callback));
+      save_as, suggested_file_name, enter.callback()));
 }
 
 int32_t ShowWithoutUserGesture0_6(PP_Resource chooser,
@@ -77,7 +77,7 @@ int32_t ShowWithoutUserGesture0_6(PP_Resource chooser,
   if (enter.failed())
     return enter.retval();
   return enter.SetResult(enter.object()->ShowWithoutUserGesture(
-      save_as, suggested_file_name, output, callback));
+      save_as, suggested_file_name, output, enter.callback()));
 }
 
 const PPB_FileChooser_Dev_0_5 g_ppb_file_chooser_0_5_thunk = {