DevTools: get rid of deviceMetics settings.

Source/devtools/front_end/overrides.css

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 66 matching lines @@
     color: inherit;
     border: none transparent;
     border-left: 4px solid #666;
 }
 
 .overrides-view fieldset {
     border: none;
     padding: 0 0 5px 15px;
 }
 
+.overrides-view fieldset p {
+    display: inline-block;
+    padding: 0;
+    margin: 0;
+    border: 0;
+}
+
+.overrides-view fieldset p label {
+    display: inline-block;
+}
+
+.overrides-view .field-error-message {
+    display: none;
+}
+
 .overrides-user-agent fieldset {
     padding-top: 5px;
 }
 
 .overrides-device > select {
     margin-bottom: 10px;
     width: 400px;
     max-width: 90%;
 }
 
@@ skipping 133 matching lines @@
     position: relative;
     top: 2px;
     background-position: -202px -107px;
     float: left;
     margin-right: 4px;
 }
 
 .overrides-view .overrides-footer .warning-icon-small {
     margin-right: 3px;
 }