diff --git a/testing/web-platform/tests/interfaces/user-timing.idl b/testing/web-platform/tests/interfaces/user-timing.idl
index 4130803ff9c4..8b0f813ba8e6 100644
--- a/testing/web-platform/tests/interfaces/user-timing.idl
+++ b/testing/web-platform/tests/interfaces/user-timing.idl
@@ -4,23 +4,23 @@
 // Source: User Timing Level 3 (https://w3c.github.io/user-timing/)
 
 dictionary PerformanceMarkOptions {
-            any detail;
-            DOMHighResTimeStamp startTime;
-        };
+    any detail;
+    DOMHighResTimeStamp startTime;
+};
 
-        dictionary PerformanceMeasureOptions {
-            any detail;
-            (DOMString or DOMHighResTimeStamp) start;
-            DOMHighResTimeStamp duration;
-            (DOMString or DOMHighResTimeStamp) end;
-        };
+dictionary PerformanceMeasureOptions {
+    any detail;
+    (DOMString or DOMHighResTimeStamp) start;
+    DOMHighResTimeStamp duration;
+    (DOMString or DOMHighResTimeStamp) end;
+};
 
-        partial interface Performance {
-            PerformanceMark mark(DOMString markName, optional PerformanceMarkOptions markOptions = {});
-            void clearMarks(optional DOMString markName);
-            PerformanceMeasure measure(DOMString measureName, optional (DOMString or PerformanceMeasureOptions) startOrMeasureOptions = {}, optional DOMString endMark);
-            void clearMeasures(optional DOMString measureName);
-        };
+partial interface Performance {
+    PerformanceMark mark(DOMString markName, optional PerformanceMarkOptions markOptions = {});
+    void clearMarks(optional DOMString markName);
+    PerformanceMeasure measure(DOMString measureName, optional (DOMString or PerformanceMeasureOptions) startOrMeasureOptions = {}, optional DOMString endMark);
+    void clearMeasures(optional DOMString measureName);
+};
 
 [Exposed=(Window,Worker),
  Constructor(DOMString markName, optional PerformanceMarkOptions markOptions)]