refactor: simplify process object initialization for sandboxed renderers (#14878)

Also fix `process.windowsStore`.

atom/common/api/atom_bindings.cc

@@ -20,6 +20,7 @@
 #include "base/process/process_metrics_iocounters.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_restrictions.h"
+#include "brightray/common/application_info.h"
 #include "native_mate/dictionary.h"
 
 namespace atom {
@@ -74,6 +75,11 @@ void AtomBindings::BindTo(v8::Isolate* isolate, v8::Local<v8::Object> process) {
   dict.Set("mas", true);
 #endif
 
+#if defined(OS_WIN)
+  if (brightray::IsRunningInDesktopBridge())
+    dict.Set("windowsStore", true);
+#endif
+
   mate::Dictionary versions;
   if (dict.Get("versions", &versions)) {
     // TODO(kevinsawicki): Make read-only in 2.0 to match node