Fix BundleData::GetBundleRootDirOutput() for non-default toolchain.

tools/gn/bundle_data.cc

Index: tools/gn/bundle_data.cc
diff --git a/tools/gn/bundle_data.cc b/tools/gn/bundle_data.cc
index 2908ddf4d43562b7a16d4f2478891a137d467059..448eac96b425f52bb54e952ebda1438e32567699 100644
--- a/tools/gn/bundle_data.cc
+++ b/tools/gn/bundle_data.cc
@@ -148,7 +148,7 @@ SourceFile BundleData::GetCompiledAssetCatalogPath() const {
 }
 
 SourceFile BundleData::GetBundleRootDirOutput(const Settings* settings) const {
-  const SourceDir& build_dir = settings->build_settings()->build_dir();
+  const SourceDir& build_dir = settings->toolchain_output_dir();
   std::string bundle_root_relative = RebasePath(root_dir().value(), build_dir);
 
   size_t first_component = bundle_root_relative.find('/');