DevTools: [lighthouse] Implement performance metrics filmstrip

third_party/WebKit/Source/devtools/front_end/Runtime.js

Index: third_party/WebKit/Source/devtools/front_end/Runtime.js
diff --git a/third_party/WebKit/Source/devtools/front_end/Runtime.js b/third_party/WebKit/Source/devtools/front_end/Runtime.js
index aa52da346f7c716c8a4ed26fc5cd9fe23f333b62..0492f72f929527bf7892188fd5aab296c5aab787 100644
--- a/third_party/WebKit/Source/devtools/front_end/Runtime.js
+++ b/third_party/WebKit/Source/devtools/front_end/Runtime.js
@@ -564,19 +564,14 @@ var Runtime = class {
   }
 
   /**
-   * @param {!Function} constructorFunction
-   * @return {!Object}
+   * @template T
+   * @param {function(new:T, ...)} constructorFunction
+   * @return {!T}
    */
   sharedInstance(constructorFunction) {
-    if (Runtime._instanceSymbol in constructorFunction)
-      return constructorFunction[Runtime._instanceSymbol];
-    var instance = new constructorFunction();
-    constructorFunction[Runtime._instanceSymbol] = instance;
-    return instance;
+    return singleton(constructorFunction);
   }
-}
-
-;
+};
 
 
 /**