Add typings for tti-polyfill (#37731)

* Add typings for tti-polyfill

* fix minValue definition

types/tti-polyfill/index.d.ts

@@ -0,0 +1,40 @@
+// Type definitions for tti-polyfill 0.2
+// Project: https://github.com/GoogleChrome/tti-polyfill#readme
+// Definitions by: Patrick Weygand <https://github.com/derduher>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+/*~ If this module is a UMD module that exposes a global variable 'myLib' when
+ *~ loaded outside a module loader environment, declare that global here.
+ *~ Otherwise, delete this declaration.
+ */
+export as namespace ttiPolyfill;
+
+/**
+ * Returns a promise that resolves to the first consistently interactive time
+ * (in milliseconds) or null if the browser doesn't support the features
+ * required for detection.
+ * ```
+ * ttiPolyfill.getFirstConsistentlyInteractive(opts).then((tti) => {
+ *   // Use `tti` value in some way.
+ * });
+ * ```
+ * @param opts Configuration options for
+ * the polyfill
+ * @return a promise that resolves to TTI
+ */
+export function getFirstConsistentlyInteractive(opts?: GetFirstConsistentlyInteractiveOpts): Promise<number|null>;
+
+export interface GetFirstConsistentlyInteractiveOpts {
+    /**
+     * When true (the default), a mutation observer is used to detect when added
+     * DOM elements will create additional network requests. This can be
+     * disabled to improve performance in cases where you know no additional
+     * request-creating DOM elements will be added.
+     */
+    useMutationObserver?: boolean;
+    /**
+     * The lower bound to start forward-searching for the quite window. If no value is set, the default is after the
+     * DOMContentLoaded event.
+     */
+    minValue?: number | null;
+}

types/tti-polyfill/tsconfig.json

@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "tti-polyfill-tests.ts"
+    ]
+}

types/tti-polyfill/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }

types/tti-polyfill/tti-polyfill-tests.ts

@@ -0,0 +1,3 @@
+import { getFirstConsistentlyInteractive } from 'tti-polyfill';
+
+getFirstConsistentlyInteractive(); // $ExpectType Promise<number | null>