Introduce two utility elements for the cpu profiler

runtime/observatory/lib/src/elements/css/shared.css

Index: runtime/observatory/lib/src/elements/css/shared.css
diff --git a/runtime/observatory/lib/src/elements/css/shared.css b/runtime/observatory/lib/src/elements/css/shared.css
index e7dab1c244cbc8aa554640c4a6184d8f1f12c286..3442d98f5b172b9b73e543f323d31d408a847d2c 100644
--- a/runtime/observatory/lib/src/elements/css/shared.css
+++ b/runtime/observatory/lib/src/elements/css/shared.css
@@ -111,6 +111,16 @@ hr {
   border-bottom-left-radius:4px;
 }
 
+.full {
+  height: 100%;
+  width: 100;
+}
+
+.flex-row {
+  display: flex;
+  flex-direction: row;
+}
+
 /* Flex row container */
 .flex-row {
   display: flex;