DevTools: fix janky transition in sensors panel

third_party/WebKit/Source/devtools/front_end/emulation/sensors.css

 /*
  * Copyright (c) 2015 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 .sensors-view {
     padding: 12px;
     display: block;
 }
@@ skipping 62 matching lines @@
 }
 
 .sensors-group-title {
     width: 80px;
     line-height: 24px;
 }
 
 .sensors-group {
     display: flex;
     flex-wrap: wrap;
+    margin-bottom: 10px;
 }
 
 .geo-fields {
     flex: 2 0 200px;
 }
 
 .latlong-group {
     display: flex;
     margin-bottom: 10px;
 }
@@ skipping 43 matching lines @@
 }
 
 .orientation-box {
     width: 66px;
     height: 122px;
     left: 0;
     right: 0;
     top: 0;
     bottom: 0;
     margin: auto;
+    transform: rotate3d(1, 0, 0, 90deg);
 }
 
-.orientation-box.is-animating {
+.orientation-box.is-animating, .is-animating .orientation-layer {
     transition: transform 300ms cubic-bezier(0.4, 0, 0.2, 1) 0ms;
 }
 
+.orientation-layer {
+    width: 100%;
+    height: 100%;
+    transform-style: preserve-3d;
+}
+
 .orientation-front,
 .orientation-back
 {
     width: 66px;
     height: 122px;
     border-radius: 8px;
 }
 
 .orientation-front {
     background-image: url(Images/accelerometer-front.png);
@@ skipping 151 matching lines @@
 
 .touch-label select {
     margin-left: 10px;
 }
 
 .panel-section-separator {
     height: 2px;
     margin-bottom: 12px;
     background: #f1f1f1;
 }