More about:gpu tracing improvements.

chrome/browser/resources/gpu_internals/timeline.css

Index: chrome/browser/resources/gpu_internals/timeline.css
diff --git a/chrome/browser/resources/gpu_internals/timeline.css b/chrome/browser/resources/gpu_internals/timeline.css
index 0c9780fb53cae713765125d43705e1df33083947..c5ebdbdd652ebf71f086b0e4d3f01185da312008 100644
--- a/chrome/browser/resources/gpu_internals/timeline.css
+++ b/chrome/browser/resources/gpu_internals/timeline.css
@@ -7,7 +7,24 @@ found in the LICENSE file.
   -webkit-user-select: none;
 }
 
-.timeline-track {
+.timeline-drag-box {
+  position: fixed;
+  background-color: rgba(0, 0, 255, 0.25);
+  border: 1px solid rgb(0, 0, 96);
+}
+
+.timeline-thread-track {
+  display: -webkit-box;
+  -webkit-box-orient: vertical;
+  padding-top: 1px;
+  padding-bottom: 1px;
+}
+
+.timeline-thread-track:not(:first-child) {
+  border-top: 1px solid #D0D0D0;
+}
+
+.timeline-slice-track {
   display: -webkit-box;
   -webkit-box-orient: horizontal;
   -webkit-box-align: stretch;
@@ -18,29 +35,19 @@ found in the LICENSE file.
   height: 18px;
 }
 
-.timeline-drag-box {
-  position: fixed;
-  background-color: rgba(0, 0, 255, 0.25);
-  border: 1px solid rgb(0, 0, 96);
-}
-
-.timeline-track:not(:first-child) {
-  border-top: 1px solid #D0D0D0
-}
-
-.timeline-track-title {
+.timeline-slice-track-title {
   text-align: right;
   overflow: visible;
   width: 150px;
   padding-right: 5px;
 }
 
-.timeline-track-canvas-container {
+.timeline-slice-track-canvas-container {
   -webkit-box-flex: 1;
   width: 100%;
 }
 
-.timeline-track-canvas {
+.timeline-slice-track-canvas {
   -webkit-box-flex: 1;
   width: 100%;
   height: 100%;