MediaPerceptionPrivate API impl and testing.

chrome/test/data/extensions/api_test/media_perception_private/state/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.
+
+let kStatusEnum = 'RUNNING'
+let state = { status: kStatusEnum }
+
+function setState() {
+  chrome.mediaPerceptionPrivate.setState(
+      state, chrome.test.callback(stateCallback));
+}
+
+function getState() {
+  chrome.mediaPerceptionPrivate.getState(
+      chrome.test.callback(stateCallback));
+}
+
+function setStateUnsettable() {
+  state.status = 'UNINITIALIZED'
+  const error = 'Settable statuses are RUNNING and SUSPENDED.'
+  chrome.mediaPerceptionPrivate.setState(state, fail(error));
+}
+
+function stateCallback(response) {
+  chrome.test.assertEq(response.status, kStatusEnum);

[tbarzic, 2017/05/09 01:28:36]

I don't think it's worth having this as a separate method.

wdyt about:

chrome.test.runTests([  function setStateTest() {
    chrome.mmp.setState('RUNNING', chrome.test.callbackPass(function(state) {
      chrome.test.assertEq({status: 'RUNNING'}, state);
    }))
  },

  function getStateTest() {
    chrome.mpp.getState(chrome.test.callbackPass(function(state) {
      chrome.test.assertEq({status: 'RUNNING'}, state);
    }));
  },
]);


Also, can you add more negative cases - e.g. invalid state, setting
deviceContext when not allowed, etc,

[Luke Sorenson, 2017/05/09 21:05:44]

Done. Fine with getting rid of the callback method, but I think its more
readable to runTests as defined methods when the number of tests is larger.

[tbarzic, 2017/05/09 21:19:14]

yes, but a couple should be OK to inline

[Luke Sorenson, 2017/05/10 18:50:16]

I've got more than a couple now :)

[tbarzic, 2017/05/11 00:38:26]

still, not too many - I find the inlined version easier to parse. but up to you.

[Luke Sorenson, 2017/05/11 23:57:58]

Acknowledged.

+}
+
+chrome.test.runTests([setState, getState]);
+