DOMUI: Refactor the new overlay style and apply it to all overlays.

chrome/browser/resources/options/options_page.css

 body {
   cursor: default;
   font-size: 100%;
 }
 
 #settings-title {
   -webkit-padding-end: 24px;
   color: #53637d;
   cursor: pointer;
   font-size: 200%;
@@ skipping 66 matching lines @@
 
 html[dir='rtl'] .close-subpage {
   float: left;
   left: 0;
 }
 
 html[hide-menu=true] .close-subpage {
   display: none
 }
 
+.content-area {
+  padding: 10px 15px 5px 15px;
+}
+
 .action-area {
   -webkit-box-align: center;
   -webkit-box-orient: horizontal;
-  bottom: 0;
+  -webkit-box-pack: end;
+  border-top: 1px solid rgba(188, 193, 208, .5);
   display: -webkit-box;
   padding: 12px;
-  position: absolute;
-  right: 0;
 }
 
 html[dir='rtl'] .action-area {
   left: 0;
 }
 
+.action-area-right {
+  display: -webkit-box;
+}
+
 .button-strip {
   -webkit-box-orient: horizontal;
   display: -webkit-box;
 }
 
 html[toolkit=views] .button-strip {
   -webkit-box-direction: reverse;
 }
 
 .button-strip > button {
   -webkit-margin-start: 10px;
   display: block;
 }
 
 .overlay .page {
-  -webkit-box-shadow: 3px 3px 3px #666;
+  -webkit-box-shadow: 0px 0px 40px -5px #888;
   background: white;
-  border: 1px solid #666;
-  border-radius: 5px;
+  border: 1px solid rgb(188, 193, 208);
+  border-radius: 2px;
   min-width: 400px;
-  padding: 0 15px 50px 15px;
+  padding: 0;
   position: relative;
 }
 
 #navbar {
   margin: 0;
 }
 
 #navbar-container {
   -webkit-border-end: 1px solid #c6c9ce;
   background: -webkit-linear-gradient(rgba(234, 238, 243, 0), #eaeef3),
@@ skipping 523 matching lines @@
 
 .suboption {
   -webkit-margin-start: 16px;
 }
 
 .link {
   margin: 10px 0;
   position: relative;
   top: 4px;
 }