[css-grid] Implementing the grid's first line baseline.

third_party/WebKit/LayoutTests/fast/css-grid-layout/resources/grid-alignment.css

 /* align-self */
 .alignSelfAuto { align-self: auto; }
 .alignSelfStretch { align-self: stretch; }
 .alignSelfStart { align-self: start; }
 .alignSelfEnd { align-self: end; }
 .alignSelfCenter { align-self: center; }
 .alignSelfRight { align-self: right; }
 .alignSelfLeft { align-self: left; }
 
 .alignSelfFlexStart { align-self: flex-start; }
 .alignSelfFlexEnd { align-self: flex-end; }
 
 .alignSelfSelfStart { align-self: self-start; }
 .alignSelfSelfEnd { align-self: self-end; }
 
 .alignSelfCenterSafe { align-self: center safe; }
 .alignSelfCenterUnsafe { align-self: center unsafe; }
 .alignSelfEndSafe { align-self: end safe; }
 .alignSelfEndUnsafe { align-self: end unsafe; }
 
+.alignSelfBaseline { align-self: baseline; }
+
 /* align-items */
 .alignItemsAuto { align-items: auto; }
 .alignItemsStretch { align-items: stretch; }
 .alignItemsStart { align-items: start; }
 .alignItemsCenter { align-items: center; }
 .alignItemsEnd { align-items: end; }
 
 .alignItemsCenterSafe { align-items: center safe; }
 .alignItemsCenterUnsafe { align-items: center unsafe; }
 .alignItemsEndSafe { align-items: end safe; }
@@ skipping 121 matching lines @@
     justify-self: left;
 }
 .selfSelfStart {
     align-self: self-start;
     justify-self: self-start;
 }
 .selfSelfEnd {
     align-self: self-end;
     justify-self: self-end;
 }
+.selfBaseline {
+    align-self: baseline;
+    justify-self: baseline;
+}
 
 /* Both align-content and justify-content */
 .contentStart {
     align-content: start;
     justify-content: start;
 }
 .contentCenter {
     align-content: center;
     justify-content: center;
 }
@@ skipping 34 matching lines @@
 
 .contentSpaceEvenly {
     justify-content: space-evenly;
     align-content: space-evenly;
 }
 
 .contentStretch {
     justify-content: stretch;
     align-content: stretch;
 }