DevTools: fix --debug-devtools flag for npm test

third_party/WebKit/Source/devtools/scripts/npm_test.js

Index: third_party/WebKit/Source/devtools/scripts/npm_test.js
diff --git a/third_party/WebKit/Source/devtools/scripts/npm_test.js b/third_party/WebKit/Source/devtools/scripts/npm_test.js
index 45223993015a138ec47ab70d22a8e418fc5f5bfd..b493f0c7ad34e7b6a853d1e0dabf3d4f0a368c85 100644
--- a/third_party/WebKit/Source/devtools/scripts/npm_test.js
+++ b/third_party/WebKit/Source/devtools/scripts/npm_test.js
@@ -233,6 +233,8 @@ function runTests(buildDirectoryPath, useDebugDevtools)
     ]);
     if (useDebugDevtools) {
         testArgs.push("--additional-driver-flag=--debug-devtools");
+    } else {
+        console.log("TIP: You can debug a test using: npm run debug-test inspector/test-name.html")
     }
     if (IS_DEBUG_ENABLED) {
         testArgs.push("--additional-driver-flag=--remote-debugging-port=9222");