DevTools: NetworkPanel: do not inject stylesheet.

Source/devtools/front_end/network/NetworkPanel.js

Index: Source/devtools/front_end/network/NetworkPanel.js
diff --git a/Source/devtools/front_end/network/NetworkPanel.js b/Source/devtools/front_end/network/NetworkPanel.js
index f09e899c2783416c020b8356123dc94347c4cdbd..ff327bc06b05d048a6f231cc04540835bbc3890a 100644
--- a/Source/devtools/front_end/network/NetworkPanel.js
+++ b/Source/devtools/front_end/network/NetworkPanel.js
@@ -1751,7 +1751,6 @@ WebInspector.NetworkPanel = function()
 {
     WebInspector.Panel.call(this, "network");
     this.registerRequiredCSS("networkPanel.css");
-    this._injectStyles();
 
     this._panelStatusBarElement = this.element.createChild("div", "panel-status-bar");
     this._filterBar = new WebInspector.FilterBar();
@@ -2065,26 +2064,6 @@ WebInspector.NetworkPanel.prototype = {
         appendRevealItem.call(this, request);
     },
 
-    _injectStyles: function()
-    {
-        var style = document.createElement("style");
-        var rules = [];
-
-        var columns = WebInspector.NetworkLogView._defaultColumnsVisibility;
-
-        var hideSelectors = [];
-        var bgSelectors = [];
-        for (var columnId in columns) {
-            hideSelectors.push("#network-container .hide-" + columnId + "-column ." + columnId + "-column");
-            bgSelectors.push(".network-log-grid.data-grid td." + columnId + "-column");
-        }
-        rules.push(hideSelectors.join(", ") + "{border-left: 0 none transparent;}");
-        rules.push(bgSelectors.join(", ") + "{background-color: rgba(0, 0, 0, 0.07);}");
-
-        style.textContent = rules.join("\n");
-        document.head.appendChild(style);
-    },
-
     __proto__: WebInspector.Panel.prototype
 }