Use Shadow DOM to display fallback content for images

LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt

Index: LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt
diff --git a/LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt b/LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt
index ee80c00dcc33cd6749cf39c2b825af6203912fdc..763a6ce1b41494e541a62abf826256ac6edaae9a 100644
--- a/LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt
+++ b/LayoutTests/platform/linux/tables/mozilla/collapsing_borders/bug41262-3-expected.txt
@@ -1,8 +1,8 @@
-layer at (0,0) size 800x679
+layer at (0,0) size 800x680
   RenderView at (0,0) size 800x600
-layer at (0,0) size 800x679
-  RenderBlock {HTML} at (0,0) size 800x679
-    RenderBody {BODY} at (8,16) size 784x647
+layer at (0,0) size 800x680
+  RenderBlock {HTML} at (0,0) size 800x680
+    RenderBody {BODY} at (8,16) size 784x648
       RenderBlock {P} at (0,0) size 784x60
         RenderText {#text} at (0,0) size 779x59
           text run at (0,0) width 441: "Following table should have 6px solid blue border around cell 3, red 5px "
@@ -89,7 +89,7 @@ layer at (0,0) size 800x679
             RenderTableCell {TD} at (102,222) size 51x55 [border: (1px solid #FF0000)] [r=4 c=2 rs=1 cs=1]
               RenderText {#text} at (17,17) size 16x19
                 text run at (17,17) width 16: "15"
-      RenderBlock {P} at (0,460) size 784x43
+      RenderBlock {P} at (0,460) size 784x44
         RenderText {#text} at (0,0) size 337x19
           text run at (0,0) width 337: "This is an example rendering for the previous table from "
         RenderInline {A} at (0,0) size 392x19 [color=#0000EE]
@@ -98,9 +98,9 @@ layer at (0,0) size 800x679
         RenderText {#text} at (729,0) size 7x19
           text run at (729,0) width 7: ": "
         RenderBR {BR} at (0,0) size 0x0
-        RenderImage {IMG} at (0,20) size 205x23
+        RenderBlock {IMG} at (0,20) size 221x24
         RenderText {#text} at (0,0) size 0x0
-      RenderBlock {P} at (0,519) size 784x40
+      RenderBlock {P} at (0,520) size 784x40
         RenderText {#text} at (0,0) size 756x39
           text run at (0,0) width 466: "Following table should have 2px solid black line between rows. There should "
           text run at (466,0) width 290: "be a total of two lines. There will be three lines if"
@@ -110,7 +110,7 @@ layer at (0,0) size 800x679
             text run at (162,23) width 112: "tr:first-child"
         RenderText {#text} at (274,20) size 4x19
           text run at (274,20) width 4: "."
-      RenderTable {TABLE} at (0,575) size 150x72 [border: (1px none #808080)]
+      RenderTable {TABLE} at (0,576) size 150x72 [border: (1px none #808080)]
         RenderTableSection {TBODY} at (0,1) size 150x71
           RenderTableRow {TR} at (0,0) size 150x24 [border: (2px solid #000000) none]
             RenderTableCell {TD} at (0,0) size 50x24 [border: (1px none #000000)] [r=0 c=0 rs=1 cs=1]
@@ -142,3 +142,10 @@ layer at (0,0) size 800x679
             RenderTableCell {TD} at (100,48) size 50x23 [border: (1px none #000000)] [r=2 c=2 rs=1 cs=1]
               RenderText {#text} at (17,2) size 16x19
                 text run at (17,2) width 16: "13"
+layer at (8,496) size 221x24 clip at (9,497) size 219x22
+  RenderBlock {DIV} at (0,0) size 221x24 [border: (1px solid #C0C0C0)]
+    RenderImage {IMG} at (2,2) size 16x16
+layer at (26,498) size 201x20
+  RenderBlock {DIV} at (18,2) size 201x20
+    RenderText {#text} at (0,0) size 201x19
+      text run at (0,0) width 201: "[Example rendering from w3.org]"