Sample builds:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux/builds/69150
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win10/builds/13748

Sample text diff:
--- E:\b\rr\tmpvf9cz_\w\layout-test-results\svg/wicd/test-rightsizing-b-expected.txt
+++ E:\b\rr\tmpvf9cz_\w\layout-test-results\svg/wicd/test-rightsizing-b-actual.txt
@@ -54,26 +54,26 @@
     layer at (0,0) size 295x150
       LayoutBlockFlow {HTML} at (0,0) size 295x150
         LayoutBlockFlow {BODY} at (8,8) size 279x134
-layer at (347,97) size 147x148
-  LayoutEmbeddedObject {object} at (299.59,2) size 147.58x147.58 [bgcolor=#FF0000]
-    layer at (0,0) size 148x148
-      LayoutView at (0,0) size 148x148
-    layer at (0,0) size 148x148
-      LayoutSVGRoot {svg} at (0,0) size 148x148
+layer at (347,95) size 147x150
+  LayoutEmbeddedObject {object} at (299.59,0) size 147.58x150 [bgcolor=#FF0000]
+    layer at (0,0) size 148x150
+      LayoutView at (0,0) size 148x150
+    layer at (0,0) size 148x150
+      LayoutBlockFlow {HTML} at (0,0) size 148x150
+        LayoutBlockFlow {BODY} at (8,8) size 132x134
+layer at (499,171) size 73x74
+  LayoutEmbeddedObject {object} at (451.61,76) size 73.78x73.78 [bgcolor=#FF0000]
+    layer at (0,0) size 74x74
+      LayoutView at (0,0) size 74x74
+    layer at (0,0) size 74x74
+      LayoutSVGRoot {svg} at (0,0) size 74x74
         LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
-        LayoutSVGRect {rect} at (0,0) size 148x148 [fill={[type=SOLID] [color=#5588FF]}] [x=-3000.00] [y=-1000.00] [width=6200.00] [height=2200.00]
-        LayoutSVGEllipse {circle} at (0,0) size 148x148 [fill={[type=SOLID] [color=#0000FF]}] [cx=100.00] [cy=100.00] [r=100.00]
-        LayoutSVGContainer {g} at (22,46) size 105x58
-          LayoutSVGText {text} at (29,62) size 142x78 contains 1 chunk(s)
-            LayoutSVGInlineText {#text} at (0,0) size 141x78
+        LayoutSVGRect {rect} at (0,0) size 74x74 [fill={[type=SOLID] [color=#5588FF]}] [x=-3000.00] [y=-1000.00] [width=6200.00] [height=2200.00]
+        LayoutSVGEllipse {circle} at (0,0) size 74x74 [fill={[type=SOLID] [color=#0000FF]}] [cx=100.00] [cy=100.00] [r=100.00]
+        LayoutSVGContainer {g} at (11,23) size 52x30
+          LayoutSVGText {text} at (29,62) size 141x80 contains 1 chunk(s)
+            LayoutSVGInlineText {#text} at (0,0) size 141x79
               chunk 1 (middle anchor) text run 1 at (29.98,125.00) startOffset 0 endOffset 3 width 140.03: "SVG"
-layer at (499,95) size 73x150
-  LayoutEmbeddedObject {object} at (451.61,0) size 73.78x150 [bgcolor=#FF0000]
-    layer at (0,0) size 74x150
-      LayoutView at (0,0) size 74x150
-    layer at (0,0) size 74x150
-      LayoutBlockFlow {HTML} at (0,0) size 74x150
-        LayoutBlockFlow {BODY} at (8,8) size 58x134
 layer at (577,95) size 37x150
   LayoutEmbeddedObject {object} at (529.83,0) size 36.89x150 [bgcolor=#FF0000]
     layer at (0,0) size 37x150

I see that there was a recent rebaseline attempt in r412906, which is likely what started causing these failures.  schenney@, can you please take a look?  I'll mark this test as flaky again in the meantime.