DevTools: zoom frames upon double click, iterate over frames using arrows.

Source/devtools/front_end/dialog.css

 .dialog {
     position: absolute;
     border: 1px solid rgb(204, 204, 204);
     box-shadow: rgb(140, 140, 140) 0 3px 14px;
     display: flex;
     -webkit-flex-direction: column;
     background: white;
 }
 
 .dialog-contents {
@@ skipping 13 matching lines @@
     margin: 0 5px;
 }
 
 .dialog button {
     background-image: linear-gradient(hsl(0, 0%, 93%), hsl(0, 0%, 93%) 38%, hsl(0, 0%, 87%));
     border: 1px solid hsla(0, 0%, 0%, 0.25);
     border-radius: 2px;
     box-shadow: 0 1px 0 hsla(0, 0%, 0%, 0.08), inset 0 1px 2px hsla(0, 100%, 100%, 0.75);
     color: hsl(0, 0%, 27%);
     font-size: 12px;
-    margin: 0 1px 0 6px;
+    margin: 0 6px 0 6px;
     text-shadow: 0 1px 0 hsl(0, 0%, 94%);
     min-height: 2em;
     padding-left: 10px;
     padding-right: 10px;
 }
 
 .dialog button:active {
     background-color: rgb(215, 215, 215);
     background-image: linear-gradient(to bottom, rgb(194, 194, 194), rgb(239, 239, 239));
 }
 
 .dialog input[type="search"]:focus,
 .dialog input[type="text"]:focus {
     outline: none;
 }