chrome/test/data/extensions/api_test/tab_capture/offscreen_end_to_end.js

// Copyright 2015 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.

// Returs a full HTML test document for the off-screen tab that renders rotating
// color fills of red, then green, then blue.
function makeRotatingColorTestDocument() {
  return makeOffscreenTabTestDocument('\
// The test pattern cycles as a color fill of red, then green, then blue.\n\
var colors = [redColor, greenColor, blueColor];\n\
\n\
function colorRotationLoop() {\n\
  if (!this.iterCount) {\n\
    this.iterCount = 1;\n\
  } else {\n\
    ++this.iterCount;\n\
  }\n\
  if (!this.stepTimeMillis) {\n\
    this.stepTimeMillis = 100;\n\
  }\n\
  var idx = this.iterCount % colors.length;\n\
  if (idx == 0) {  // Completed a cycle.\n\
    // Increase the wait time between switching test patterns for\n\
    // overloaded bots that are not capturing all the frames of video.\n\
    this.stepTimeMillis *= 1.25;\n\
  }\n\
  setFillColor(colors[idx]);\n\
  setTimeout(colorRotationLoop, this.stepTimeMillis);\n\
}\n\
colorRotationLoop();');
}

// Observer side of this end-to-end test.  |stream| is monitored for each of the
// three fill colors to be generated by the off-screen tab.  Once all three have
// been observed, the test ends successfully.
function waitForExpectedColorsAndEndTest(stream) {
  // Elements from this array are removed as each color is observed.  When it
  // becomes empty, the test succeeds.
  var remainingColors = [[255, 0, 0], [0, 255, 0], [0, 0, 255]];
  // TODO(crbug/758057): Determine why color accuracy went down in this test
  // with the new VIZ-based tab capturer.
  var colorDeviation = 50;

  function onMatchedNextColor(idx) {
    chrome.test.assertTrue(idx < remainingColors.length);
    remainingColors.splice(idx, 1);
    if (remainingColors.length == 0) {
      stopAllTracks(stream);
      chrome.test.succeed();
    } else {
      waitForAnExpectedColor(stream, remainingColors, colorDeviation,
                             onMatchedNextColor);
    }
  }
  waitForAnExpectedColor(stream, remainingColors, colorDeviation,
                         onMatchedNextColor);
}

chrome.test.runTests([
  function offscreenTabTest() {
    chrome.tabCapture.captureOffscreenTab(
        makeDataUriFromDocument(makeRotatingColorTestDocument()),
        getCaptureOptions(),
        waitForExpectedColorsAndEndTest);
  }
]);