feat: add chrome.runtime.getManifest (#16891)

* feat: add chrome.runtime.getManifest

* Add test for chrome.runtime.getManifest

* Use IPC utils for getManifest internals

spec/fixtures/extensions/chrome-api/main.js

@@ -0,0 +1,15 @@
+/* global chrome */
+
+const testMap = {
+  getManifest () {
+    const manifest = chrome.runtime.getManifest()
+    console.log(JSON.stringify(manifest))
+  }
+}
+
+const dispatchTest = (event) => {
+  const testName = event.data
+  const test = testMap[testName]
+  test()
+}
+window.addEventListener('message', dispatchTest, false)

spec/fixtures/extensions/chrome-api/manifest.json

@@ -0,0 +1,12 @@
+{
+  "name": "chrome-api",
+  "version": "1.0",
+  "content_scripts": [
+    {
+      "matches": ["<all_urls>"],
+      "js": ["main.js"],
+      "run_at": "document_start"
+    }
+  ],
+  "manifest_version": 2
+}