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

third_party/WebKit/LayoutTests/platform/linux/fast/repaint/block-layout-inline-children-replaced-expected.txt

 {
   "bounds": [800, 600],
   "children": [
     {
       "bounds": [800, 600],
       "contentsOpaque": true,
       "drawsContent": true,
       "repaintRects": [
         [155, 37, 92, 100],
         [0, 37, 402, 100],
         [0, 36, 402, 152]
       ],
       "paintInvalidationClients": [
         "LayoutBlockFlow DIV id='target' class='target'",
+        "RootInlineBox",
         "LayoutImage IMG",
         "InlineBox",
         "RootInlineBox",
         "LayoutBlockFlow DIV id='target' class='target'",
         "LayoutImage IMG"
       ]
     }
   ]
 }