Bug 206842

When importing WPT tests, the WebKit WPT importer tries to rewrite any URL() reference inside the <style> tags of the ref-tests to fix issues related to moving the ref-test to a new directory.
But its currently only doing that for the first URL() reference it finds.

Example:

1) WPT test css/css-backgrounds/css-border-radius-002.html has as test reference css/css-backgrounds/reference/css-border-radius-ref-002.html 
2) WPT test importer imports css/css-backgrounds/reference/css-border-radius-ref-002.html as css/css-backgrounds/css-border-radius-002-expected.html 
3) Since the ref-test has been moved to a different directory, it tries to update relative urls() on the <style> tag:

Originally css-border-radius-ref-002.html had:
    <style type="text/css">
        .redSquare {
            position: absolute;
			left:50px;
            width: 100px;
            height: 100px;
			background-image:url(../support/yyy.png);
        }
		.greenSquare {
            position: absolute;
			left:50px;
            width: 100px;
            height: 100px;
			background-image:url(../support/yy.png);
        }
        .container {
            position: absolute;
        }
    </style>

Therefore, the style on css-border-radius-002-expected.html should have been rewrote as:
    <style type="text/css">
        .redSquare {
            position: absolute;
			left:50px;
            width: 100px;
            height: 100px;
			background-image:url(support/yyy.png);
        }
		.greenSquare {
            position: absolute;
			left:50px;
            width: 100px;
            height: 100px;
			background-image:url(support/yy.png);
        }
        .container {
            position: absolute;
        }
    </style>
    
    

The problem it is currently doing that only for the first URL (yyy.png) but not for the second (yy.png)