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

tools/gn/test_with_scope.cc

Index: tools/gn/test_with_scope.cc
diff --git a/tools/gn/test_with_scope.cc b/tools/gn/test_with_scope.cc
index 0ddd4636be4299de4a1972edf7214bbdc45f7046..b239c640052da0610105d89e6b70df623be44860 100644
--- a/tools/gn/test_with_scope.cc
+++ b/tools/gn/test_with_scope.cc
@@ -10,13 +10,22 @@
 #include "tools/gn/parser.h"
 #include "tools/gn/tokenizer.h"
 
+namespace {
+
+BuildSettings CreateBuildSettingsForTest() {
+  BuildSettings build_settings;
+  build_settings.SetBuildDir(SourceDir("//out/Debug/"));
+  return build_settings;
+}
+
+}  // namespace
+
 TestWithScope::TestWithScope()
-    : build_settings_(),
+    : build_settings_(CreateBuildSettingsForTest()),
       settings_(&build_settings_, std::string()),
       toolchain_(&settings_, Label(SourceDir("//toolchain/"), "default")),
       scope_(&settings_),
       scope_progammatic_provider_(&scope_, true) {
-  build_settings_.SetBuildDir(SourceDir("//out/Debug/"));
   build_settings_.set_print_callback(
       base::Bind(&TestWithScope::AppendPrintOutput, base::Unretained(this)));