Bug 1019217 - Use HDPI asset for Web Audio editor sidebar icon. r=bgrins

browser/themes/shared/devtools/webaudioeditor.inc.css

@@ -125,6 +125,11 @@ text {
   -moz-image-region: rect(0px,16px,16px,0px);
 }
 
+#inspector-pane-toggle > .toolbarbutton-icon {
+  width: 16px;
+  height: 16px;
+}
+
 #inspector-pane-toggle[pane-collapsed] {
   list-style-image: url(debugger-expand.png);
 }
@@ -132,3 +137,18 @@ text {
 #inspector-pane-toggle:active {
   -moz-image-region: rect(0px,32px,16px,16px);
 }
+
+@media (min-resolution: 2dppx) {
+  #inspector-pane-toggle {
+    list-style-image: url(debugger-collapse@2x.png);
+    -moz-image-region: rect(0px,32px,32px,0px);
+  }
+
+  #inspector-pane-toggle[pane-collapsed] {
+    list-style-image: url(debugger-expand@2x.png);
+  }
+
+  #inspector-pane-toggle:active {
+    -moz-image-region: rect(0px,64px,32px,32px);
+  }
+}