Make script-insets obey their bounds, and other padding tweaks.

runtime/observatory/lib/src/elements/function_view.html

 <link rel="import" href="../../../../packages/polymer/polymer.html">
 <link rel="import" href="class_ref.html">
 <link rel="import" href="code_ref.html">
 <link rel="import" href="function_ref.html">
 <link rel="import" href="library_ref.html">
 <link rel="import" href="observatory_element.html">
 <link rel="import" href="nav_bar.html">
 <link rel="import" href="script_inset.html">
 <link rel="import" href="script_ref.html">
 <link rel="import" href="view_footer.html">
@@ skipping 78 matching lines @@
          </div>
          <template if="{{ function.name != function.vmName }}">
            <div class="memberItem">
              <div class="memberName">vm name</div>
              <div class="memberValue">{{ function.vmName }}</div>
            </div>
          </template>
        </div>
     </div>
 
-    <hr>
-    <script-inset script="{{ function.script }}"
-                  startPos="{{ function.tokenPos }}"
-                  endPos="{{ function.endTokenPos }}">
-    </script-inset>
+    <div class="content-centered-big">
+      <hr>
+      <script-inset script="{{ function.script }}"
+                    startPos="{{ function.tokenPos }}"
+                    endPos="{{ function.endTokenPos }}">
+      </script-inset>
+    </div>
 
     <view-footer></view-footer>
   </template>
 </polymer-element>
 
 <script type="application/dart" src="function_view.dart"></script>