[DevTools] Prepare to move Popover to shadow DOM.

third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html

Index: third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html
diff --git a/third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html b/third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html
index 8edd25c9a8f4566e22e7780dd63e6e7097def3c6..42de865238da1da36a1d0f83ec1394f49a4fe2c8 100644
--- a/third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html
+++ b/third_party/WebKit/LayoutTests/inspector/tracing/timeline-network/timeline-network-resource-details.html
@@ -35,7 +35,11 @@ function test()
             var rows = element.querySelectorAll(".timeline-details-view-row");
             for (var i = 0; i < rows.length; ++i) {
                 var title = rows[i].firstChild.firstChild.textContent;
-                var value = rows[i].lastChild.firstChild.textContent;
+                var value = rows[i].lastChild.firstChild;
+                if (value.children && value.children.length)
+                  value = Array.from(value.children, element => element.textContent).slice(1).join('');
+                else
+                  value = value.textContent;
                 if (title === "Duration" || title === "Mime Type")
                     value = typeof value;
                 if (/^file:\/\//.test(value))