Need to repaint its ::first-line background when a block moves.

third_party/WebKit/LayoutTests/fast/repaint/inline-block-resize-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
         [8, 8, 100, 100],
         [8, 8, 100, 100]
       ],
       "paintInvalidationClients": [
         "RootInlineBox",
         "InlineBox",
         "LayoutBlockFlow (positioned) DIV",
+        "RootInlineBox",
         "LayoutBlockFlow DIV id='target'"
       ]
     }
   ]
 }