Bug 1247929 patch 5 - Remove spurious canvas rule from reftests. r=dholbert

This removes a rule that was incorrectly added in the tests in patch 3,
which dholbert pointed out in a review comment (comment 18) made after
granting review (and only 3 minutes before I pushed the patches), which
I didn't see before pushing them.

I had incorrectly copied that rule from the
min-intrinsic-with-percents-across-elements.html test, which I based
these on.

MozReview-Commit-ID: IARSYkKkIRx

layout/reftests/css-sizing/min-intrinsic-with-max-width-percents-across-form-controls-ref.html

@@ -17,10 +17,6 @@ td:nth-child(2) {
 
 td:nth-child(1) > * { visibility: hidden; vertical-align: bottom }
 
-canvas {
-  background: blue
-}
-
 </style>
 
 <table><tr>

layout/reftests/css-sizing/min-intrinsic-with-max-width-percents-across-form-controls.html

@@ -17,10 +17,6 @@ td:nth-child(2) {
 
 td:nth-child(1) > * { visibility: hidden; vertical-align: bottom; max-width: 100% }
 
-canvas {
-  background: blue
-}
-
 </style>
 
 <table><tr>

layout/reftests/css-sizing/min-intrinsic-with-width-percents-across-form-controls-ref.html

@@ -17,10 +17,6 @@ td:nth-child(2) {
 
 td:nth-child(1) > * { visibility: hidden; vertical-align: bottom }
 
-canvas {
-  background: blue
-}
-
 </style>
 
 <table><tr>

layout/reftests/css-sizing/min-intrinsic-with-width-percents-across-form-controls.html

@@ -17,10 +17,6 @@ td:nth-child(2) {
 
 td:nth-child(1) > * { visibility: hidden; vertical-align: bottom; width: 100% }
 
-canvas {
-  background: blue
-}
-
 </style>
 
 <table><tr>