New tabCapture.captureOffscreenTab API, initially for Presentation API 1UA mode

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

Index: chrome/test/data/extensions/api_test/tab_capture/offscreen_end_to_end.js
diff --git a/chrome/test/data/extensions/api_test/tab_capture/offscreen_end_to_end.js b/chrome/test/data/extensions/api_test/tab_capture/offscreen_end_to_end.js
new file mode 100644
index 0000000000000000000000000000000000000000..e073d0704e03704b23355de8402bbbeb768b7af6
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/tab_capture/offscreen_end_to_end.js
@@ -0,0 +1,64 @@
+// 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]];
+  var colorDeviation = 10;
+
+  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);
+  }
+]);