Inconsistent use of [x] close panel icon. Code changes.

ui/webui/resources/css/expandable_bubble.css

Index: ui/webui/resources/css/expandable_bubble.css
diff --git a/ui/webui/resources/css/expandable_bubble.css b/ui/webui/resources/css/expandable_bubble.css
index ee4bc03dbc2c7a77f99df62d33e3bf09cbdc205a..a5b51b5d80d429b2dde64ecff6bd8b9d67cab27b 100644
--- a/ui/webui/resources/css/expandable_bubble.css
+++ b/ui/webui/resources/css/expandable_bubble.css
@@ -74,18 +74,18 @@
 
 .expandable-bubble-close {
   background-image: -webkit-image-set(
-      url('../../../resources/default_100_percent/close_bar.png') 1x,
-      url('../../../resources/default_200_percent/close_bar.png') 2x);
+      url('../../../resources/default_100_percent/close_2.png') 1x,
+      url('../../../resources/default_200_percent/close_2.png') 2x);
 }
 
 .expandable-bubble-close:hover {
   background-image: -webkit-image-set(
-      url('../../../resources/default_100_percent/close_bar_hover.png') 1x,
-      url('../../../resources/default_200_percent/close_bar_hover.png') 2x);
+      url('../../../resources/default_100_percent/close_2_hover.png') 1x,
+      url('../../../resources/default_200_percent/close_2_hover.png') 2x);
 }
 
 .expandable-bubble-close:active {
   background-image: -webkit-image-set(
-    url('../../../resources/default_100_percent/close_bar_pressed.png') 1x,
-    url('../../../resources/default_200_percent/close_bar_pressed.png') 2x);
+      url('../../../resources/default_100_percent/close_2_pressed.png') 1x,
+      url('../../../resources/default_200_percent/close_2_pressed.png') 2x);
 }