Add UMA metric to track usage of sending a mousedown to select elements.

third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html

Index: third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html
diff --git a/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html b/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html
index 5180e03d18c88eba778f7d6f5bf194e7639704fc..f87074899a5bf6b516f69da8510a94b8475a3f1a 100644
--- a/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html
+++ b/third_party/WebKit/LayoutTests/imported/wpt/html/semantics/grouping-content/the-ol-element/grouping-ol-start-reftest-001-expected.html
@@ -5,7 +5,6 @@
     <title>ol element</title>
     <link rel="author" title="dzenana" href="mailto:dzenana.trenutak@gmail.com">
     <link rel="help" href="https://html.spec.whatwg.org/multipage/#the-ol-element">
-    <link rel="match" href="grouping-ol-start-reftest-001.html" />
     <meta name="assert" content="Sequences produced by calculated values for LI elements within OL match spec's expectations. (part one)" />
     <style type="text/css">
         span p {display:list-item; margin-left: 0; margin-top: 0; margin-bottom: 0; padding-left: 0; padding-top: 0; padding-bottom: 0;}