DOMUI Prefs: Small style fixes for Basics page.

- Adds spacing under the header on all subpages (preventing, e.g., lists from abutting the header underline)
- Aligns the "Add" button to the left edge of the list above it, and adds space between the two.
- Fixes the left-side padding of the new <select> style.

BUG=None
TEST=Spacing on startup page manager subpage should be better.

Review URL: http://codereview.chromium.org/6299011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71869 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/options/browser_options_page.css

@@ -74,3 +74,8 @@
   position: absolute;
   bottom: 18px;
 }
+
+#startupAddButton {
+  margin-left: 0;
+  margin-top: 10px;
+}

chrome/browser/resources/options/options_page.css

@@ -277,6 +277,7 @@ html[hide-menu=true] #mainview {
 
 .subpage-sheet .page h1 {
   padding-top: 4px;
+  margin-bottom: 10px;
 }
 
 section {
@@ -587,7 +588,7 @@ select {
   font-size: inherit;
   margin: 0;
   overflow: hidden;
-  padding: 2px 20px 2px 3px;
+  padding: 2px 20px 2px 12px;
   text-overflow: ellipsis;
   white-space: nowrap;
 }