DevTools: make toolbar button click targets square

Source/devtools/front_end/timeline/timelinePanel.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 10 matching lines @@
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 .panel.timeline > .toolbar {
-    border-bottom: 1px solid #f1f1f1;
+    border-bottom: 1px solid #dadada;
 }
 
 #timeline-overview-panel {
     flex: none;
     position: relative;
     border-bottom: 1px solid rgb(140, 140, 140);
 }
 
 #timeline-overview-panel .timeline-graph-bar {
     pointer-events: none;
 }
 
 .timeline-records-title, .timeline-records-list {
-    background-color: #eee;
+    background-color: #f3f3f3;
 }
 
 .timeline-records-title {
     padding: 3px 3px 3px 5px;
     flex: 0 0 19px;
     color: rgb(92, 110, 129); text-shadow: rgba(255, 255, 255, 0.75) 0 1px 0;
 }
 
 .timeline-records-list {
     flex: auto;
@@ skipping 561 matching lines @@
 
 .timeline-details-view {
     color: #333;
     overflow: hidden;
 }
 
 .timeline-details-view-body {
     flex: auto;
     overflow: auto;
     position: relative;
-    background-color: #eee;
+    background-color: #f3f3f3;
 }
 
 .timeline-details-view-block {
     flex: none;
     display: flex;
     flex-direction: column;
 }
 
 .timeline-details-view-row {
     display: flex;
@@ skipping 228 matching lines @@
 .timeline-gap {
     flex: none;
 }
 
 .timeline-filmstrip-preview {
     margin-top: 10px;
     max-width: 200px;
     max-height: 200px;
     cursor: pointer;
 }