testharnessreport: Hide elements in tests by removing them from the document tree, instead of visibi

LayoutTests/resources/testharnessreport.js

Index: LayoutTests/resources/testharnessreport.js
diff --git a/LayoutTests/resources/testharnessreport.js b/LayoutTests/resources/testharnessreport.js
index 86873d816e61c752327b272df1fe76d378a4aae1..b05aeb333a0145c91eaa359fd9eeb2589c3f21f5 100644
--- a/LayoutTests/resources/testharnessreport.js
+++ b/LayoutTests/resources/testharnessreport.js
@@ -103,14 +103,7 @@ add_completion_callback(function (tests, harness_status) {
             if ((isCSSWGTest() || isJSTest()) && logDiv) {
                 // Assume it's a CSSWG style test, and anything other than the log div isn't
                 // material to the testrunner output, so should be hidden from the text dump
-                var next = null;
-                for (var child = document.body.firstChild; child; child = next) {
-                    next = child.nextSibling;
-                    if (child.nodeType == Node.ELEMENT_NODE)
-                        child.style.visibility = "hidden";
-                    else if (child.nodeType == Node.TEXT_NODE)
-                        document.body.removeChild(child);
-                }
+                document.body.textContent = '';
             }
         }