DevTools: preload treeoutline triangles image

third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js

Index: third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js b/third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js
index f044821e2059c05596dc68e98919d189a46aa7e6..e96283686b8b751539fc057943b61a12cebc452f 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js
@@ -1213,3 +1213,12 @@ UI.TreeElement = class {
 
 /** @const */
 UI.TreeElement._ArrowToggleWidth = 10;
+
+(function() {

[pfeldman, 2017/02/13 18:18:12]

Is this temporary? I wish all the generic images were a part of a single sprite.

+  var img = new Image();
+  if (window.devicePixelRatio > 1)
+    img.src = 'Images/treeoutlineTriangles_2x.png';
+  else
+    img.src = 'Images/treeoutlineTriangles.png';
+  UI.TreeElement._imagePreload = img;
+})();