PPAPI: Implement operator= for FileChooser_Trusted.

ppapi/cpp/trusted/file_chooser_trusted.cc

Index: ppapi/cpp/trusted/file_chooser_trusted.cc
diff --git a/ppapi/cpp/trusted/file_chooser_trusted.cc b/ppapi/cpp/trusted/file_chooser_trusted.cc
index d0c6c50679e099bf94042174637d92646c080c9a..bd13dd7a9f5822c2f53ad3211ff6befdd8b6746b 100644
--- a/ppapi/cpp/trusted/file_chooser_trusted.cc
+++ b/ppapi/cpp/trusted/file_chooser_trusted.cc
@@ -40,6 +40,14 @@ FileChooser_Trusted::FileChooser_Trusted(const FileChooser_Trusted& other)
       suggested_file_name_(other.suggested_file_name_) {
 }
 
+FileChooser_Trusted& FileChooser_Trusted::operator=(
+    const FileChooser_Trusted& other) {
+  FileChooser_Dev::operator=(other);
+  save_as_ = other.save_as_;
+  suggested_file_name_ = other.suggested_file_name_;
+  return *this;
+}
+
 int32_t FileChooser_Trusted::Show(const CompletionCallback& cc) {
   if (!has_interface<PPB_FileChooserTrusted>())
     return cc.MayForce(PP_ERROR_NOINTERFACE);