Use Shadow DOM to display fallback content for images

LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt

Index: LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt
diff --git a/LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt b/LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt
index 675beb93af4133ed95a48d0e939c0509caf1b687..a0a2f0a29b87ef24475d39a84d4939db1303e9a0 100644
--- a/LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt
+++ b/LayoutTests/platform/linux/tables/mozilla/bugs/bug60807-expected.txt
@@ -11,19 +11,19 @@ layer at (0,0) size 800x600
                 RenderText {#text} at (1,1) size 94x19
                   text run at (1,1) width 94: "MERCHANT"
             RenderTableCell {TD} at (132,9) size 5x3 [border: (1px inset #808080)] [r=0 c=1 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (137,0) size 304x22 [border: (1px inset #808080)] [r=0 c=2 rs=1 cs=1]
               RenderInline {B} at (0,0) size 110x19
                 RenderText {#text} at (97,1) size 110x19
                   text run at (97,1) width 110: "DESCRIPTION"
             RenderTableCell {TD} at (441,9) size 5x3 [border: (1px inset #808080)] [r=0 c=3 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (446,0) size 78x22 [border: (1px inset #808080)] [r=0 c=4 rs=1 cs=1]
               RenderInline {B} at (0,0) size 48x19
                 RenderText {#text} at (29,1) size 48x19
                   text run at (29,1) width 48: "PRICE"
             RenderTableCell {TD} at (524,9) size 5x3 [border: (1px inset #808080)] [r=0 c=5 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (529,0) size 69x22 [border: (1px inset #808080)] [r=0 c=6 rs=1 cs=1]
               RenderInline {B} at (0,0) size 39x19
                 RenderText {#text} at (15,1) size 39x19
@@ -36,22 +36,36 @@ layer at (0,0) size 800x600
                 RenderText {#text} at (1,1) size 89x15
                   text run at (1,1) width 89: "American Starlex"
             RenderTableCell {TD} at (132,9) size 5x3 [border: (1px inset #808080)] [r=0 c=1 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (137,2) size 304x18 [border: (1px inset #808080)] [r=0 c=2 rs=1 cs=1]
               RenderInline {FONT} at (0,0) size 239x15
                 RenderText {#text} at (1,1) size 239x15
                   text run at (1,1) width 239: "Digital_Cameras DC200 New|In stock; Kodak"
             RenderTableCell {TD} at (441,9) size 5x3 [border: (1px inset #808080)] [r=0 c=3 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (446,2) size 78x18 [border: (1px inset #808080)] [r=0 c=4 rs=1 cs=1]
               RenderInline {FONT} at (0,0) size 39x15
                 RenderText {#text} at (38,1) size 39x15
                   text run at (38,1) width 39: "$270.00"
             RenderTableCell {TD} at (524,9) size 5x3 [border: (1px inset #808080)] [r=0 c=5 rs=1 cs=1]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
             RenderTableCell {TD} at (529,0) size 69x22 [border: (1px inset #808080)] [r=0 c=6 rs=1 cs=1]
               RenderText {#text} at (17,1) size 35x19
                 text run at (17,1) width 35: "More"
           RenderTableRow {TR} at (0,22) size 598x3
             RenderTableCell {TD} at (0,22) size 598x3 [bgcolor=#000000] [border: (1px inset #808080)] [r=1 c=0 rs=1 cs=8]
-              RenderImage {IMG} at (1,1) size 1x1
+              RenderBlock {IMG} at (1,1) size 1x1
+layer at (142,19) size 4x4 clip at (143,20) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (451,19) size 4x4 clip at (452,20) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (534,19) size 4x4 clip at (535,20) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (142,43) size 4x4 clip at (143,44) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (451,43) size 4x4 clip at (452,44) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (534,43) size 4x4 clip at (535,44) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]
+layer at (10,56) size 4x4 clip at (11,57) size 2x2
+  RenderBlock {DIV} at (0,0) size 4x4 [border: (1px solid #C0C0C0)]