DOMUI prefs: Widen sidebar and content

chrome/browser/resources/options/browser_options_page.css

 #startupPages {
   border: solid 1px #999999;
   height: 100px;
 }
 
 #customHomePageGroup {
   display: -webkit-box;
   -webkit-box-orient: horizontal;
 }
 
@@ skipping 14 matching lines @@
 }
 
 #defaultSearchEngineGroup > div {
   display: -webkit-box;
   -webkit-box-orient: horizontal;
 }
 
 #defaultSearchEngine {
   display: block;
   -webkit-box-flex: 1;
+  max-width: 300px;
 }
 
 #defaultSearchManageEnginesButton {
   margin-top: 0px;
   -webkit-margin-start: 10px;
 }
 
 #defaultBrowserState {
   margin-top: 6px;
 }
 
 #instantOption {
   margin-bottom: 0px;
 }
 
 #instantConfirmText {
   font-family: inherit;
   white-space: pre-wrap;
   width: 500px;
 }
 
 #instantConfirmLearnMore {
   position: absolute;
   bottom: 18px;
 }