Check for inputs not generated by deps

tools/gn/build_settings.cc

Index: tools/gn/build_settings.cc
diff --git a/tools/gn/build_settings.cc b/tools/gn/build_settings.cc
index 3ffb8283ef0acd42eed262c0caa48f067a242df8..63ff35845cb7db16e87141ab9fd2d8fc867875f8 100644
--- a/tools/gn/build_settings.cc
+++ b/tools/gn/build_settings.cc
@@ -7,7 +7,8 @@
 #include "base/files/file_util.h"
 #include "tools/gn/filesystem_utils.h"
 
-BuildSettings::BuildSettings() {
+BuildSettings::BuildSettings()
+    : check_for_bad_items_(true) {
 }
 
 BuildSettings::BuildSettings(const BuildSettings& other)
@@ -17,7 +18,8 @@ BuildSettings::BuildSettings(const BuildSettings& other)
       python_path_(other.python_path_),
       build_config_file_(other.build_config_file_),
       build_dir_(other.build_dir_),
-      build_args_(other.build_args_) {
+      build_args_(other.build_args_),
+      check_for_bad_items_(true) {
 }
 
 BuildSettings::~BuildSettings() {