Move section CSS to uber_shared to share with other uber pages.

chrome/browser/resources/uber/uber_shared.css

Index: chrome/browser/resources/uber/uber_shared.css
diff --git a/chrome/browser/resources/uber/uber_shared.css b/chrome/browser/resources/uber/uber_shared.css
index b74a413539be9e253a2fc910d5de401a0b016ac0..2a8f9bc129d8f4bbff7f6822b8bf6b4c66690f9d 100644
--- a/chrome/browser/resources/uber/uber_shared.css
+++ b/chrome/browser/resources/uber/uber_shared.css
@@ -95,3 +95,24 @@ body.uber-frame footer {
   min-width: 600px;
   padding: 8px 0;
 }
+
+/* Sections are used in options pages, help page and history page. This defines
+ * the section metrics to match the header metrics above. */
+body.uber-frame section {
+  -webkit-padding-start: 18px;
+  margin-bottom: 24px;
+  margin-top: 8px;
+  max-width: 600px;
+}
+
+body.uber-frame section:last-of-type {
+  margin-bottom: 0;
+}
+
+body.uber-frame section > h3 {
+  -webkit-margin-start: -18px;
+}
+
+body.uber-frame section > div:only-of-type {
+  -webkit-box-flex: 1;
+}