TimelineFlameChart: selectRecord implementation

Source/devtools/front_end/flameChart.css

 .overview-container {
     overflow: hidden;
     position: absolute;
     top: 0;
     width: 100%;
     height: 80px;
 }
 
 .chart-container {
     flex: auto;
 }
 
 #flame-chart-overview-grid .resources-dividers-label-bar {
     pointer-events: auto;
 }
 
+.flame-chart-main-pane {
+    overflow: hidden;
+}
+
 .flame-chart-overview-pane {
     flex: 0 0 80px !important;
 }
 
 #flame-chart-overview-container {
     border-bottom: 1px solid rgba(0, 0, 0, 0.3);
 }
 
 .flame-chart-overview-canvas {
     position: absolute;
@@ skipping 13 matching lines @@
 
 .chart-container .entry-info .title {
     font-weight: bold;
 }
 
 .flame-chart-highlight-element {
     background-color: black;
     position: absolute;
     opacity: 0.2;
     pointer-events: none;
-}
+}
+
+.flame-chart-selected-element {
+    position: absolute;
+    pointer-events: none;
+    border-color: rgb(56, 121, 217);
+    border-width: 2px;
+    border-style: solid;
+    background-color: rgba(56, 121, 217, 0.2);
+}