Test fragment scrolling and history restoration interaction w/ scroll anchoring.

third_party/WebKit/LayoutTests/fast/layout/scroll-anchoring/fragment-scrolling-anchors.html

+<script src="../../../resources/js-test.js"></script>
+<style>
+  body {
+    margin: 0px; height: 2000px; width: 2000px;

[ojan, 2016/04/19 21:34:24]

Not a big deal, but the de facto standard for tests is to put each css property
on its own line for easier readability.

[ymalik, 2016/04/22 20:41:05]

Done.

+  }
+
+  #first {
+    height: 1000px; background-color: #FFA5D2;
+  }
+
+  #anchor {
+    position: absolute; background-color: #84BE6A;
+    height: 600px; width: 100%;
+  }
+
+  #fragment {
+    position: relative; background-color: orange;
+    height: 200px; width: 200px; margin: 10px;
+  }
+</style>
+
+<script>
+window.jsTestIsAsync = true;
+setPrintTestResultsLazily();
+
+description("This test ensures that scroll anchoring interacts correctly with\

[ojan, 2016/04/19 21:34:24]

We don't usually have a line length limit on layout tests.

[ymalik, 2016/04/22 20:41:05]

This is removed in the new test.

+    fragment scrolls.");
+
+onload = function() {
+    if (!window.internals) {
+        finishJSTest();
+        return;
+    }
+
+    internals.settings.setScrollAnchoringEnabled(true);
+
+    // Scroll to fragment.
+    window.location.hash = 'fragment';
+    requestAnimationFrame(function() {
+        // Height of first + fragment margin-top.
+        shouldBe('document.scrollingElement.scrollTop', '1010');
+
+        // Change height of content above fragment.
+        var ch = document.getElementById('changer');
+        ch.style.height = 100;
+        // Height of first + height changer + fragment margin-top.
+        shouldBe('document.scrollingElement.scrollTop', '1110');
+        finishJSTest();
+    });
+}
+</script>
+
+<div id="first"></div>
+<div id="changer"></div>
+<div id="anchor">
+    <div id="fragment" name="fragment"></div>
+</div>