DevTools: Refactor network panel overview

Source/devtools/front_end/network/networkPanel.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 148 matching lines @@
 .network-timing-bar.connecting,
 .network-timing-bar.blocking {
     height: 10px;
     margin: auto;
 }
 
 .resource-timing-view .network-timing-table {
     width: 100%;
 }
 
+#network-overview-panel {
+    flex: none;
+    position: relative;
+}
+
 #network-overview-container {
     overflow: hidden;
     flex: auto;
     display: flex;
+    flex-direction: column;
     position: relative;
     border-bottom: 1px solid #CDCDCD;
 }
 
-.network-overview-canvas-container {
-    position: absolute;
-    top: 0;
-    right: 0;
-    bottom: 0;
-    left: 0;
-    z-index: 200;
-}
-
-.network-overview-canvas-container canvas {
-    width: 100%;
-    height: 100%;
-}
-
-#network-overview-grid {
-    flex: auto;
+#network-overview-grid .resources-dividers-label-bar {
+    pointer-events: auto;
 }
 
 .network .network-overview {
     flex: 0 0 100px;
 }
 
 .network-overview .overview-grid-window,
 .network-overview .overview-grid-dividers-background {
     height: 100%;
 }
@@ skipping 17 matching lines @@
 .request-view.html iframe {
     width: 100%;
     height: 100%;
     position: absolute;
 }
 
 .network-film-strip {
     border-bottom: solid 1px #cdcdcd;
     flex: none !important;
 }