DevTools: Preview of .svg file is not seen in Network section of dev tools.

BUG=510345

Review URL: https://codereview.chromium.org/1291733003

git-svn-id: svn://svn.chromium.org/blink/trunk@200857 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/devtools/front_end/network/xmlView.css

@@ -14,7 +14,7 @@
     list-style: none;
     padding: 0;
     margin: 0;
-    -webkit-padding-start: 16px; /* step width + arrow width */
+    -webkit-padding-start: 16px;/* step width + arrow width */
 }
 
 .shadow-xml-view > ol {
@@ -25,20 +25,18 @@
     display: none;
 }
 
-.shadow-xml-view li {
-  display: flex;
-  align-items: center;
-}
-
 .shadow-xml-view li.parent::before {
-  -webkit-user-select: none;
-  -webkit-mask-image: url(Images/toolbarButtonGlyphs.png);
-  -webkit-mask-size: 352px 144px;
-  -webkit-mask-position: -4px -97px;
-  background-color: rgb(110, 110, 110);
-  content: "";
-  width: 10px; /* arrow width */
-  height: 10px;
+    -webkit-user-select: none;
+    -webkit-mask-image: url(Images/toolbarButtonGlyphs.png);
+    -webkit-mask-size: 352px 144px;
+    -webkit-mask-position: -4px -97px;
+    background-color: rgb(110, 110, 110);
+    content: " ";
+    width: 10px;/* arrow width */
+    height: 10px;
+    display: inline-block;
+    position: relative;
+    top: 2px;
 }
 
 .shadow-xml-view li.parent.expanded::before {