MediaPerceptionPrivate API impl and testing.

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

+// 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');

[tbarzic, 2017/05/17 21:04:42]

assertEq({status: 'RUNNING'}, state);

(and generally, the expected value should be the first arg)

[Luke Sorenson, 2017/05/17 23:07:49]

Done.

+      }));
+    },
+    function getDiagnostics() {
+      chrome.mediaPerceptionPrivate.getDiagnostics(
+          chrome.test.callbackPass(function(response) {
+            chrome.test.assertEq(
+                response.perceptionSamples[0].framePerception.frameId, 1);

[tbarzic, 2017/05/17 21:04:42]

assertEq({
  perceptionSamples: [{
    framePerception: {
      frameId: 1
    }
  }]
}, response);

And I'd consider adding more data to the diagnostics data

[Luke Sorenson, 2017/05/17 23:07:49]

I think that is covered in the ProtoToIdl test. Otherwise, adding more data here
is just verifying that the idl -> JS dictionary conversion works.

+          }));
+    }
+]);