LayoutTests/tiled-drawing/background-transparency-toggle.html - WebKit - Git at Google

 <!DOCTYPE html>

 <html>
 <head>
     <style>
         body {
             background-color: white;
             height: 1000px;
         }

         body.transparent {
             background-color: rgba(0, 0, 0, 0.2);
         }
     </style>
     <script>
         if (window.testRunner) {
             testRunner.dumpAsText();
             testRunner.waitUntilDone();
         }

         function documentLoaded()
         {
             window.setTimeout(doTest, 0);
         }

         function appendLayerDump()
         {
             if (window.internals)
                 document.getElementById('output').textContent += window.internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_TILE_CACHES);
         }

         function doTest()
         {
             if (window.internals)
                 internals.setViewBaseBackgroundColor('transparent');
             appendLayerDump();

             document.body.classList.add('transparent');
             appendLayerDump();

             document.body.classList.remove('transparent');
             appendLayerDump();

             if (window.internals)
                 internals.setViewBaseBackgroundColor('white');

             document.body.classList.add('transparent');
             appendLayerDump();

             if (window.testRunner)
                 testRunner.notifyDone();
         }

         window.addEventListener('load', documentLoaded, false);
     </script>
 </head>
 <body>

 <p>Page tiles should be transparent if the body's background has alpha.</p>
 <div id="test"></div>
 <pre id="output"></pre>

 </body>
 </html>
	<!DOCTYPE html>

	<html>
	<head>
	<style>
	body {
	background-color: white;
	height: 1000px;
	}

	body.transparent {
	background-color: rgba(0, 0, 0, 0.2);
	}
	</style>
	<script>
	if (window.testRunner) {
	testRunner.dumpAsText();
	testRunner.waitUntilDone();
	}

	function documentLoaded()
	{
	window.setTimeout(doTest, 0);
	}

	function appendLayerDump()
	{
	if (window.internals)
	document.getElementById('output').textContent += window.internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_TILE_CACHES);
	}

	function doTest()
	{
	if (window.internals)
	internals.setViewBaseBackgroundColor('transparent');
	appendLayerDump();

	document.body.classList.add('transparent');
	appendLayerDump();

	document.body.classList.remove('transparent');
	appendLayerDump();

	if (window.internals)
	internals.setViewBaseBackgroundColor('white');

	document.body.classList.add('transparent');
	appendLayerDump();

	if (window.testRunner)
	testRunner.notifyDone();
	}

	window.addEventListener('load', documentLoaded, false);
	</script>
	</head>
	<body>

	<p>Page tiles should be transparent if the body's background has alpha.</p>
	<div id="test"></div>
	<pre id="output"></pre>

	</body>
	</html>