MediaPerceptionPrivate API impl and testing.

chrome/test/data/extensions/api_test/media_perception_private/diagnostics/runtest.js

Index: chrome/test/data/extensions/api_test/media_perception_private/diagnostics/runtest.js
diff --git a/chrome/test/data/extensions/api_test/media_perception_private/diagnostics/runtest.js b/chrome/test/data/extensions/api_test/media_perception_private/diagnostics/runtest.js
new file mode 100644
index 0000000000000000000000000000000000000000..5ff0b367b571c78e1c184cde23d5b01f9f1ae78d
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/media_perception_private/diagnostics/runtest.js
@@ -0,0 +1,21 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+chrome.test.runTests([
+    function setStateRunning() {
+      // Need to start the mocked media analytics process.
+      chrome.mediaPerceptionPrivate.setState({
+        status: 'RUNNING'
+      }, chrome.test.callbackPass(function(state) {
+        chrome.test.assertEq(state.status, 'RUNNING');
+      }));
+    },
+    function getDiagnostics() {
+      chrome.mediaPerceptionPrivate.getDiagnostics(
+          chrome.test.callbackPass(function(response) {
+            chrome.test.assertEq(
+                response.perceptionSamples[0].framePerception.frameId, 1);
+          }));
+    }
+]);