DevTools: fixed UI glitches of inlined DataGrid.

Source/devtools/front_end/dataGrid.css

 .data-grid {
     position: relative;
     border: 1px solid #aaa;
     font-size: 11px;
     line-height: 120%;
 }
 
 .data-grid .highlight {
     background-color: rgb(255, 230, 179);
 }
@@ skipping 21 matching lines @@
 }
 
 .data-grid.inline {
     border-left: none;
 }
 
 .data-grid.inline .data-container {
     position: static;
 }
 
+.data-grid.inline col.corner,
 .data-grid.inline th.corner,
 .data-grid.inline td.corner {
     display: none;
 }
 
 .data-grid th.corner,
 .data-grid td.corner,
 .data-grid col.corner {
     width: 14px;
     padding-right: 0;
@@ skipping 39 matching lines @@
 .data-grid td,
 .data-grid th {
     white-space: nowrap;
     text-overflow: ellipsis;
     overflow: hidden;
     height: 16px; /* Keep in sync with .data-grid table.data @ background-size */
     line-height: 14px;
     border-left: 1px solid #aaa;
 }
 
-.data-grid th:first-child,
-.data-grid td:first-child {
+.data-grid:not(.inline) th:first-child,
+.data-grid:not(.inline) td:first-child {
     border-left: none !important;
 }
 
 .data-grid td {
     vertical-align: top;
     padding: 1px 4px;
     -webkit-user-select: text;
 }
 
 .data-grid th {
@@ skipping 130 matching lines @@
     text-indent: 10px;
 }
 
 .data-grid-resizer {
     position: absolute;
     top: 0;
     bottom: 0;
     width: 5px;
     z-index: 500;
 }