Preload scan external CSS for @import

third_party/WebKit/Source/core/frame/Settings.in

Index: third_party/WebKit/Source/core/frame/Settings.in
diff --git a/third_party/WebKit/Source/core/frame/Settings.in b/third_party/WebKit/Source/core/frame/Settings.in
index 8fdfaa02af164f01c562b1f1e00110702b26d9ef..0e527f94f26e76f081066212b7e93f656e55c74d 100644
--- a/third_party/WebKit/Source/core/frame/Settings.in
+++ b/third_party/WebKit/Source/core/frame/Settings.in
@@ -412,8 +412,14 @@ useDefaultImageInterpolationQuality initial=false
 # Variant of the ParseHTMLOnMainThread experiment. One experiment immediately
 # tokenizes input bytes. The default is to tokenize with a post task.
 parseHTMLOnMainThreadSyncTokenize initial=false
+
 # Variant of the ParseHTMLOnMainThread experiment. This is designed to coalesce
 # TokenizedChunks when the experiment is running in threaded mode.
 parseHTMLOnMainThreadCoalesceChunks initial=false
 
+# Whether the CSSPreloadScanner is used for externally CSS preloads. NoPreload
+# indicates that the scanner will be used, but no preloads issued.
+cssExternalScannerNoPreload initial=false
+cssExternalScannerPreload initial=false
+
 browserSideNavigationEnabled initial=false