DevTools: convert a few more icons to UI.Icon.

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

Index: third_party/WebKit/Source/devtools/front_end/network/blockedURLsPane.css
diff --git a/third_party/WebKit/Source/devtools/front_end/network/blockedURLsPane.css b/third_party/WebKit/Source/devtools/front_end/network/blockedURLsPane.css
index 280be41f242a43ee7ca7099fc9f966128ec4e5ec..0e20e389ca5422a34c06063aab06e7e1751c92be 100644
--- a/third_party/WebKit/Source/devtools/front_end/network/blockedURLsPane.css
+++ b/third_party/WebKit/Source/devtools/front_end/network/blockedURLsPane.css
@@ -63,28 +63,15 @@
     margin-right: 5px;
 }
 
-.blocked-url .remove-button {
-    width: 13px;
-    height: 13px;
-    background-image: url(Images/toolbarButtonGlyphs.png);
-    background-size: 352px 168px;
-    background-position: -175px -96px;
-    visibility: hidden;
-    flex: none;
+.remove-icon {
     opacity: 0.7;
-    cursor: default;
+    visibility: hidden;
 }
 
-@media (-webkit-min-device-pixel-ratio: 1.1) {
-.blocked-url .remove-button {
-    background-image: url(Images/toolbarButtonGlyphs_2x.png);
+.blocked-url .remove-icon:hover {
+    opacity: 1.0;
 }
-} /* media */
 
-.blocked-url:hover .remove-button {
+.blocked-url:hover .remove-icon {
     visibility: visible;
 }
-
-.blocked-url .remove-button:hover {
-    opacity: 1.0;
-}