DevTools: Move network request instrumentation points for timeline down the stack.

third_party/WebKit/Source/devtools/front_end/timeline/TimelineNetworkFlameChart.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @implements {PerfUI.FlameChartDataProvider}
  * @unrestricted
  */
 Timeline.TimelineFlameChartNetworkDataProvider = class {
   constructor() {
@@ skipping 209 matching lines @@
       context.lineTo(begin, y + tickHeightPx / 2);
       context.moveTo(begin, y);
       context.lineTo(end, y);
     }
 
     context.lineWidth = 1;
     context.strokeStyle = '#ccc';
     var lineY = Math.floor(barY + barHeight / 2) + 0.5;
     var leftTick = Math.floor(unclippedBarX) + 0.5;
     var rightTick = end - 0.5;
-    drawTick(leftTick, sendStart, lineY);
+    if (request.startTime)
+      drawTick(leftTick, sendStart, lineY);
     drawTick(rightTick, finish, lineY);
     context.stroke();
 
     if (typeof request.priority === 'string') {
       var color = this._colorForPriority(request.priority);
       if (color) {
         context.fillStyle = color;
         context.fillRect(sendStart + 0.5, barY + 0.5, 3.5, 3.5);
       }
     }
@@ skipping 145 matching lines @@
 
   /**
    * @override
    * @param {number} entryIndex
    * @return {boolean}
    */
   canJumpToEntry(entryIndex) {
     return false;
   }
 };