[CSS Grid Layout] Fix positioned grid children position and size

LayoutTests/fast/css-grid-layout/resources/grid.css

Index: LayoutTests/fast/css-grid-layout/resources/grid.css
diff --git a/LayoutTests/fast/css-grid-layout/resources/grid.css b/LayoutTests/fast/css-grid-layout/resources/grid.css
index ae58bd31da251a0ad3f9ccdde26e59a1c1c9c1c2..4c5400096d7ba05ff720f61ce673913505bb9f02 100644
--- a/LayoutTests/fast/css-grid-layout/resources/grid.css
+++ b/LayoutTests/fast/css-grid-layout/resources/grid.css
@@ -21,24 +21,54 @@
     grid-row: 1;
 }
 
+.onlyFirstRowOnlyFirstColumn {
+    background-color: blue;
+    grid-column: 1 / 2;
+    grid-row: 1 / 2;
+}
+
 .firstRowSecondColumn {
     background-color: lime;
     grid-column: 2;
     grid-row: 1;
 }
 
+.onlyFirstRowOnlySecondColumn {
+    background-color: lime;
+    grid-column: 2 / 3;
+    grid-row: 1 / 2;
+}
+
 .secondRowFirstColumn {
     background-color: purple;
     grid-column: 1;
     grid-row: 2;
 }
 
+.onlySecondRowOnlyFirstColumn {
+    background-color: purple;
+    grid-column: 1 / 2;
+    grid-row: 2 / 3;
+}
+
 .secondRowSecondColumn {
     background-color: orange;
     grid-column: 2;
     grid-row: 2;
 }
 
+.onlySecondRowOnlySecondColumn {
+    background-color: orange;
+    grid-column: 2 / 3;
+    grid-row: 2 / 3;
+}
+
+.endSecondRowEndSecondColumn {
+    background-color: orange;
+    grid-column-end: 3;
+    grid-row-end: 3;
+}
+
 .firstAutoRowSecondAutoColumn {
     grid-row: 1 / auto;
     grid-column: 2 / auto;