diff --git a/layout/reftests/bidi/413928-1-ref.html b/layout/reftests/bidi/413928-1-ref.html
index a814fcd16d8b..e8679fcc84c4 100644
--- a/layout/reftests/bidi/413928-1-ref.html
+++ b/layout/reftests/bidi/413928-1-ref.html
@@ -5,7 +5,7 @@
   <title>Bug 413928</title>
   <style type="text/css">
 .li {
-  line-height: 24px;
+  line-height: 2em;
 }
 .list-number-he {
   direction: rtl;
diff --git a/layout/reftests/bidi/413928-1.html b/layout/reftests/bidi/413928-1.html
index e615659cb45e..de722d606ffd 100644
--- a/layout/reftests/bidi/413928-1.html
+++ b/layout/reftests/bidi/413928-1.html
@@ -12,7 +12,7 @@
 }
 
  li {
-   line-height: 24px;
+   line-height: 2em;
 }
   </style>
  </head>
diff --git a/layout/reftests/bidi/413928-2-ref.html b/layout/reftests/bidi/413928-2-ref.html
index 41efd95a17ac..5cd9cd76aa52 100644
--- a/layout/reftests/bidi/413928-2-ref.html
+++ b/layout/reftests/bidi/413928-2-ref.html
@@ -5,7 +5,7 @@
   <title>Bug 413928</title>
   <style type="text/css">
 .li {
-  line-height: 24px;
+  line-height: 2em;
 }
 .list-number-he {
   direction: rtl;
diff --git a/layout/reftests/bidi/413928-2.html b/layout/reftests/bidi/413928-2.html
index 3b09bb9f74c8..a81e92c44ed7 100644
--- a/layout/reftests/bidi/413928-2.html
+++ b/layout/reftests/bidi/413928-2.html
@@ -12,7 +12,7 @@
 }
 
  li {
-   line-height: 24px;
+   line-height: 2em;
 }
   </style>
  </head>
diff --git a/layout/reftests/box-shadow/boxshadow-inner-basic-ref.html b/layout/reftests/box-shadow/boxshadow-inner-basic-ref.html
index a89032165937..9564a01a7d4c 100644
--- a/layout/reftests/box-shadow/boxshadow-inner-basic-ref.html
+++ b/layout/reftests/box-shadow/boxshadow-inner-basic-ref.html
@@ -1 +1,12 @@
-<div style="background-color: grey; width: 300px; height: 300px; -moz-border-radius: 5px; position: absolute; top: 20px; left: 20px;">inset</div><div style="-moz-border-radius: 5px; width: 300px; height: 300px; background-color: white; position: absolute; top: 40px; left: 40px;">&nbsp;</div>
+<body style="font-size: 16px;">
+<div style="background-color: grey;
+  width: 15em; height: 15em;
+  -moz-border-radius: 0.5em;
+  position: absolute;
+  top: 1em; left: 1em;">inset</div>
+<div style="-moz-border-radius: 0.5em;
+  width: 15em; height: 15em;
+  background-color: white;
+  position: absolute;
+  top: 3em; left: 3em;">&nbsp;</div>
+</body>
diff --git a/layout/reftests/box-shadow/boxshadow-inner-basic.html b/layout/reftests/box-shadow/boxshadow-inner-basic.html
index 968e665f3adb..38d402c2e09e 100644
--- a/layout/reftests/box-shadow/boxshadow-inner-basic.html
+++ b/layout/reftests/box-shadow/boxshadow-inner-basic.html
@@ -1 +1,7 @@
-<div style="-moz-box-shadow: 20px 20px grey inset; width: 300px; height: 300px; -moz-border-radius: 5px; position: absolute; top: 20px; left: 20px;">inset</div>
+<body style="font-size: 16px;">
+<div style="-moz-box-shadow: 2em 2em grey inset;
+  width: 15em; height: 15em;
+  -moz-border-radius: .5em;
+  position: absolute;
+  top: 1em; left: 1em;">inset</div>
+</body>
diff --git a/layout/reftests/bugs/134706-5-ref.html b/layout/reftests/bugs/134706-5-ref.html
index d6227dcd421c..aa2216f7fe15 100644
--- a/layout/reftests/bugs/134706-5-ref.html
+++ b/layout/reftests/bugs/134706-5-ref.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 10px; }
+
 	</style>
 </head>
 <body>
diff --git a/layout/reftests/bugs/134706-5.html b/layout/reftests/bugs/134706-5.html
index 1e56bb08de1c..6cff106c81f4 100644
--- a/layout/reftests/bugs/134706-5.html
+++ b/layout/reftests/bugs/134706-5.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 10px; }
+
 	table { margin: 0; border-spacing: 0; }
 	td, th { padding: 0; vertical-align: top; }
 
diff --git a/layout/reftests/bugs/134706-6-ref.html b/layout/reftests/bugs/134706-6-ref.html
index d1e960a89e12..1818962865c1 100644
--- a/layout/reftests/bugs/134706-6-ref.html
+++ b/layout/reftests/bugs/134706-6-ref.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/134706-6.html b/layout/reftests/bugs/134706-6.html
index f65147805e2f..824bc7e43b01 100644
--- a/layout/reftests/bugs/134706-6.html
+++ b/layout/reftests/bugs/134706-6.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/134706-6b-ref.html b/layout/reftests/bugs/134706-6b-ref.html
index e1e4b4d87e2a..33812d3023d7 100644
--- a/layout/reftests/bugs/134706-6b-ref.html
+++ b/layout/reftests/bugs/134706-6b-ref.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/134706-6b.html b/layout/reftests/bugs/134706-6b.html
index 6c0fa16d1a11..2b049de037d6 100644
--- a/layout/reftests/bugs/134706-6b.html
+++ b/layout/reftests/bugs/134706-6b.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/134706-6c-ref.html b/layout/reftests/bugs/134706-6c-ref.html
index eebfc8a34386..b3cf10ba37b8 100644
--- a/layout/reftests/bugs/134706-6c-ref.html
+++ b/layout/reftests/bugs/134706-6c-ref.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/134706-6c.html b/layout/reftests/bugs/134706-6c.html
index ef1fbdf866e8..317933486757 100644
--- a/layout/reftests/bugs/134706-6c.html
+++ b/layout/reftests/bugs/134706-6c.html
@@ -6,6 +6,8 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
+
 	table { margin: 0; border-spacing: 0; }
 	caption, td, th { padding: 0; vertical-align: top; text-align: left; }
 
diff --git a/layout/reftests/bugs/262151-1-ref.html b/layout/reftests/bugs/262151-1-ref.html
index b200285483e0..c3450685c65a 100644
--- a/layout/reftests/bugs/262151-1-ref.html
+++ b/layout/reftests/bugs/262151-1-ref.html
@@ -3,7 +3,7 @@
 <head>
   <title>Bug 262151 Reference</title>
 </head>
-<body style="text-align: right">
+<body style="text-align: right; font-size: 16px;">
 <span>This text should all </span><span>be on one line.</span>
 </body>
 </html>
diff --git a/layout/reftests/bugs/262151-1.html b/layout/reftests/bugs/262151-1.html
index d66fa81c2e59..f47cd2518787 100644
--- a/layout/reftests/bugs/262151-1.html
+++ b/layout/reftests/bugs/262151-1.html
@@ -4,7 +4,7 @@
   <title>Bug 262151</title>
   <style type="text/css">table {border-collapse: collapse} td {padding: 0px}</style>
 </head>
-<body>
+<body style="font-size: 16px;">
 <table width="100%">
   <tr>
     <td><div style="width: 20em"></div></td>
diff --git a/layout/reftests/bugs/322436-1-ref.html b/layout/reftests/bugs/322436-1-ref.html
index 52fa2de4bf0d..4e69fda15b54 100644
--- a/layout/reftests/bugs/322436-1-ref.html
+++ b/layout/reftests/bugs/322436-1-ref.html
@@ -6,7 +6,11 @@
 
 <body>
 There should be floating text here!  Look at the source!
-This text should show up
+This&nbsp;text&nbsp;should&nbsp;show&nbsp;up
+<!-- using non-breaking spaces here because the box in the testcase
+     will always wrap (or not) as a complete unit, depending on
+     font size and window width -->
+
 </body>
 
 </html>
diff --git a/layout/reftests/bugs/322436-1.html b/layout/reftests/bugs/322436-1.html
index c6337e4a62bb..64c32a8b8fb1 100644
--- a/layout/reftests/bugs/322436-1.html
+++ b/layout/reftests/bugs/322436-1.html
@@ -6,7 +6,9 @@
 
 <body>
 There should be floating text here!  Look at the source!
-<div style="display: -moz-box;"><div style="float: left;">This text should show up</div></div>
+<div style="display: -moz-box;"><div style="float: left;">This&nbsp;text&nbsp;should&nbsp;show&nbsp;up</div></div>
+<!-- using non-breaking spaces here to match the reference -->
+
 </body>
 
 </html>
diff --git a/layout/reftests/bugs/388980-1-ref.html b/layout/reftests/bugs/388980-1-ref.html
index a1b61ae6fda5..5c5e4277f959 100644
--- a/layout/reftests/bugs/388980-1-ref.html
+++ b/layout/reftests/bugs/388980-1-ref.html
@@ -3,7 +3,7 @@
 <title>Reftest for bug 388980</title></html>
 <script type="text/javascript">
 
-var text = '<html><head></head><body>'
+var text = '<html><head></head><body style="font-size:16px;">'
 	+ '<p style="background-color:red;">This paragraph should be red</p>'
 	+ '<p style="background-color:blue;">This paragraph should be blue</p>'
 	+ '<p>This paragraph should not be colored</p>'
diff --git a/layout/reftests/bugs/388980-1.html b/layout/reftests/bugs/388980-1.html
index 3fe0536b44ac..827bd260eb74 100644
--- a/layout/reftests/bugs/388980-1.html
+++ b/layout/reftests/bugs/388980-1.html
@@ -3,7 +3,7 @@
 <title>Reftest for bug 388980</title></html>
 <script type="text/javascript">
 
-var text = '<html><head></head><body>'
+var text = '<html><head></head><body style="font-size:16px;">'
 	+ '<p id="redpar">This paragraph should be red</p>'
 	+ '<p id="bluepar">This paragraph should be blue</p>'
 	+ '<p id="normalpar">This paragraph should not be colored</p>'
diff --git a/layout/reftests/bugs/404149-1-ref.xul b/layout/reftests/bugs/404149-1-ref.xul
index 71d26d8e937b..c69173983b45 100644
--- a/layout/reftests/bugs/404149-1-ref.xul
+++ b/layout/reftests/bugs/404149-1-ref.xul
@@ -9,6 +9,7 @@ label {
   padding: 0 2px 0;
   margin: 0 10px 0 -58px;
   font-family: Scheherazade;
+  font-size: 16px;
 }
 " ?>
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
diff --git a/layout/reftests/bugs/404149-1.xul b/layout/reftests/bugs/404149-1.xul
index e52336d08ca7..7d28fbb7e7e8 100644
--- a/layout/reftests/bugs/404149-1.xul
+++ b/layout/reftests/bugs/404149-1.xul
@@ -9,6 +9,7 @@ label {
   padding: 0 2px 0;
   margin: 0 10px 0 -58px;
   font-family: Scheherazade;
+  font-size: 16px;
 }
 " ?>
 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
diff --git a/layout/reftests/bugs/410621-1-ref.html b/layout/reftests/bugs/410621-1-ref.html
index d5ae4d19ee19..49a51d5cec4d 100644
--- a/layout/reftests/bugs/410621-1-ref.html
+++ b/layout/reftests/bugs/410621-1-ref.html
@@ -11,7 +11,7 @@ table {
 </style>
 </head>
 <body>
-<div style="height: 300px;">
+<div style="height: 20em;">
  <table align="left">
   <tr>
    <td>Entry 1</td>
diff --git a/layout/reftests/bugs/410621-1.html b/layout/reftests/bugs/410621-1.html
index 47da1619ad6c..38b04b8f03c8 100644
--- a/layout/reftests/bugs/410621-1.html
+++ b/layout/reftests/bugs/410621-1.html
@@ -11,7 +11,7 @@ table {
 </style>
 </head>
 <body>
-<div style="overflow: auto; height: 300px;">
+<div style="overflow: auto; height: 20em;">
  <table align="left">
   <tr>
    <td>Entry 1</td>
diff --git a/layout/reftests/bugs/413286-1a.html b/layout/reftests/bugs/413286-1a.html
index 7d14e65e11f3..495072b168bd 100644
--- a/layout/reftests/bugs/413286-1a.html
+++ b/layout/reftests/bugs/413286-1a.html
@@ -1,7 +1,7 @@
 <html>
   <head>
     <style>
-      table     { width: 400px; height: 25px; }
+      table     { width: 400px; height: 25px; font-size: 10px; }
       td.blue   { background: lightblue;  color: rgba(0,0,0,0) }
       td.green  { background: lightgreen; color: rgba(0,0,0,0) }
       col.a     { width: 100px; }
diff --git a/layout/reftests/bugs/413286-1b.html b/layout/reftests/bugs/413286-1b.html
index a0d00a393a93..d2e125b24a9f 100644
--- a/layout/reftests/bugs/413286-1b.html
+++ b/layout/reftests/bugs/413286-1b.html
@@ -1,7 +1,7 @@
 <html>
   <head>
     <style>
-      table     { width: 400px; height: 25px; }
+      table     { width: 400px; height: 25px; font-size: 10px; }
       td.blue   { background: lightblue;  color: rgba(0,0,0,0) }
       td.green  { background: lightgreen; color: rgba(0,0,0,0) }
       col.a     { width: 25%;   }
diff --git a/layout/reftests/bugs/413286-1c.html b/layout/reftests/bugs/413286-1c.html
index 3781b689692e..7e4b1db3c0cf 100644
--- a/layout/reftests/bugs/413286-1c.html
+++ b/layout/reftests/bugs/413286-1c.html
@@ -1,7 +1,7 @@
 <html>
   <head>
     <style>
-      table     { width: 400px; height: 25px; }
+      table     { width: 400px; height: 25px; font-size: 10px; }
       td.blue   { background: lightblue;  color: rgba(0,0,0,0) }
       td.green  { background: lightgreen; color: rgba(0,0,0,0) }
       col.a     { width: 100px; }
diff --git a/layout/reftests/bugs/417676-ref.html b/layout/reftests/bugs/417676-ref.html
index 44b2643aaece..5f35eabd6b3e 100644
--- a/layout/reftests/bugs/417676-ref.html
+++ b/layout/reftests/bugs/417676-ref.html
@@ -5,14 +5,14 @@
   html, body { margin: 0; padding: 0; }
 </style>
 
-<div style="width: 3in; border: solid;">
+<div style="width: 3in; border: solid; font-size: 16px;">
 This box must be repeated at this same position on the first, second, and third pages.
 </div>
 
-<div style="page-break-before: always; width: 3in; border: solid;">
+<div style="page-break-before: always; width: 3in; border: solid; font-size: 16px;">
 This box must be repeated at this same position on the first, second, and third pages.
 </div>
 
-<div style="page-break-before: always; width: 3in; border: solid;">
+<div style="page-break-before: always; width: 3in; border: solid; font-size: 16px;">
 This box must be repeated at this same position on the first, second, and third pages.
 </div>
diff --git a/layout/reftests/bugs/417676.html b/layout/reftests/bugs/417676.html
index 75a85cd80f5e..a27fa30b1fcb 100644
--- a/layout/reftests/bugs/417676.html
+++ b/layout/reftests/bugs/417676.html
@@ -2,7 +2,7 @@
 <html class="reftest-print">
 <title>Fixed Positioning Test</title>
 
-<div style="position: fixed; left: 0; top: 0; width: 3in; border: solid;">
+<div style="position: fixed; left: 0; top: 0; width: 3in; border: solid; font-size: 16px;">
 This box must be repeated at this same position on the first, second, and third pages.
 </div>
 
diff --git a/layout/reftests/bugs/424236-9-ref.html b/layout/reftests/bugs/424236-9-ref.html
index 710ac509596a..2bc8c95a4d72 100644
--- a/layout/reftests/bugs/424236-9-ref.html
+++ b/layout/reftests/bugs/424236-9-ref.html
@@ -7,6 +7,7 @@
 	<meta http-equiv="Content-Style-Type" content="text/css">
 	<style type="text/css">
 
+	body { font-size: 16px; }
 	* { -moz-outline-offset: -1px; outline-offset: -1px; }
 	body > span { outline: 1px dotted black; }
 	/* can't compare to border combined with negative margin because of
diff --git a/layout/reftests/bugs/430813-3-ref.html b/layout/reftests/bugs/430813-3-ref.html
index 3303b954194e..52706c614f74 100644
--- a/layout/reftests/bugs/430813-3-ref.html
+++ b/layout/reftests/bugs/430813-3-ref.html
@@ -7,7 +7,7 @@
 <body>
 <div style="margin-bottom: 1px">text</div>
 <div style="float:left;width:90px;height:300px"></div>
-<div style="margin-left:90px">
+<div style="margin-left:90px; font-size: 16px;">
 <span style="padding:0.2em;">This text should be near the top of the page, not pushed below the float.</span>
 </div>
 </body>
diff --git a/layout/reftests/bugs/430813-3.html b/layout/reftests/bugs/430813-3.html
index 8225e9793446..ed58d3d27a7a 100644
--- a/layout/reftests/bugs/430813-3.html
+++ b/layout/reftests/bugs/430813-3.html
@@ -7,7 +7,8 @@
 <body>
 <div style="margin-bottom: 1px">text</div>
 <div style="float:left;width:90px;height:300px"></div>
-<div style="overflow:hidden">
+<div style="overflow:hidden; font-size: 16px;">
+<!-- restrict size to prevent wrap, can lead to antialiasing problem in the test -->
 <span style="padding:0.2em;">This text should be near the top of the page, not pushed below the float.</span>
 </div>
 </body>
diff --git a/layout/reftests/bugs/433640-1-ref.html b/layout/reftests/bugs/433640-1-ref.html
index 49ff9596a47c..697eb58255bc 100644
--- a/layout/reftests/bugs/433640-1-ref.html
+++ b/layout/reftests/bugs/433640-1-ref.html
@@ -14,7 +14,7 @@
   
   body > div { height:100px; }
   
-  p { height:20px; }
+  p { font-size: 12px; height:20px; }
 </style>
 </head><body>
 
diff --git a/layout/reftests/bugs/433640-1.html b/layout/reftests/bugs/433640-1.html
index fb6d4635959e..2dbb26cfa081 100644
--- a/layout/reftests/bugs/433640-1.html
+++ b/layout/reftests/bugs/433640-1.html
@@ -17,7 +17,7 @@
 
   /* ensure that font heights do not affect image placement. Fractional image offsets can
      affect exactly which pixel rects get painted. */
-  p { height:20px; }
+  p { font-size: 12px; height:20px; }
 </style>
 </head><body>
 
diff --git a/layout/reftests/bugs/433700-ref.html b/layout/reftests/bugs/433700-ref.html
index d23189d2cff9..f341a0377fd9 100644
--- a/layout/reftests/bugs/433700-ref.html
+++ b/layout/reftests/bugs/433700-ref.html
@@ -3,8 +3,10 @@
     <title>Testcase for bug 433700</title>
     <style type="text/css">
 
+body { font-size: 16px; }
+
 fieldset,legend { padding:0; margin:0; border-width:0; border-style:solid; }
-fieldset { border-right:7px solid blue; }
+fieldset { border-right:7px solid blue; font-size: 16px; }
 
 #test1 { position:fixed; }
 #test1 fieldset { background:lime;}
diff --git a/layout/reftests/bugs/433700.html b/layout/reftests/bugs/433700.html
index 2728392d2a6d..7d13d5ff043b 100644
--- a/layout/reftests/bugs/433700.html
+++ b/layout/reftests/bugs/433700.html
@@ -3,8 +3,10 @@
     <title>Testcase for bug 433700</title>
     <style type="text/css">
 
+body { font-size: 16px; }
+
 fieldset,legend { padding:0; margin:0; border-width:0; border-style:solid; }
-fieldset { border-right:7px solid blue; }
+fieldset { border-right:7px solid blue; font-size: 16px; }
 
 #test1 { position:fixed; }
 #test1 fieldset { padding-left:35px; border-left:25px solid lime; background:lime; }
diff --git a/layout/reftests/font-face/media-query-remove-1.html b/layout/reftests/font-face/media-query-remove-1.html
index bb1361ffc0e2..1b3071738f84 100644
--- a/layout/reftests/font-face/media-query-remove-1.html
+++ b/layout/reftests/font-face/media-query-remove-1.html
@@ -14,7 +14,7 @@
 	function run() {
 		var iframe = document.getElementsByTagName("iframe")[0]
 		iframe.contentWindow.arm();
-		iframe.style.width = "100px";
+		iframe.style.width = "5em";
 	}
 
 	</script>
diff --git a/layout/reftests/margin-collapsing/inline-block-sibling-1-ref.html b/layout/reftests/margin-collapsing/inline-block-sibling-1-ref.html
index c867d54bd515..41eba9c76cb9 100644
--- a/layout/reftests/margin-collapsing/inline-block-sibling-1-ref.html
+++ b/layout/reftests/margin-collapsing/inline-block-sibling-1-ref.html
@@ -1,6 +1,8 @@
 <!DOCTYPE html>
 <html>
 <head>
+<!-- specifying all heights in em units so that large font sizes
+     don't disrupt relationships; everything will scale together -->
 <style type="text/css">
 #a {
  width: 200px;
@@ -8,12 +10,12 @@
 }
 #b, #c {
  display: inline-block;
- height: 20px; width: 200px;
+ height: 2em; width: 200px;
  background-color: blue;
  vertical-align: bottom;
 }
 #b {
- margin-bottom: 20px;
+ margin-bottom: 2em;
 }
 </style>
 </head>
diff --git a/layout/reftests/margin-collapsing/inline-block-sibling-1a.html b/layout/reftests/margin-collapsing/inline-block-sibling-1a.html
index 14963f9fb810..8466dc0be38f 100644
--- a/layout/reftests/margin-collapsing/inline-block-sibling-1a.html
+++ b/layout/reftests/margin-collapsing/inline-block-sibling-1a.html
@@ -8,15 +8,15 @@
 }
 #b, #c {
  display: inline-block;
- height: 20px; width: 200px;
+ height: 2em; width: 200px;
  background-color: blue;
  vertical-align: bottom;
 }
 #b {
- margin-bottom: 5px;
+ margin-bottom: .5em;
 }
 #c {
- margin-top: 15px;
+ margin-top: 1.5em;
 }
 </style>
 </head>
diff --git a/layout/reftests/margin-collapsing/inline-block-sibling-1b.html b/layout/reftests/margin-collapsing/inline-block-sibling-1b.html
index 994617d20cc2..0e288cb43250 100644
--- a/layout/reftests/margin-collapsing/inline-block-sibling-1b.html
+++ b/layout/reftests/margin-collapsing/inline-block-sibling-1b.html
@@ -8,15 +8,15 @@
 }
 #b, #c {
  display: inline-block;
- height: 20px; width: 200px;
+ height: 2em; width: 200px;
  background-color: blue;
  vertical-align: bottom;
 }
 #b {
- margin-bottom: 15px;
+ margin-bottom: 1.5em;
 }
 #c {
- margin-top: 5px;
+ margin-top: .5em;
 }
 </style>
 </head>
diff --git a/layout/reftests/margin-collapsing/inline-block-sibling-1c.html b/layout/reftests/margin-collapsing/inline-block-sibling-1c.html
index 4f9eee5ad835..6c8848666726 100644
--- a/layout/reftests/margin-collapsing/inline-block-sibling-1c.html
+++ b/layout/reftests/margin-collapsing/inline-block-sibling-1c.html
@@ -8,15 +8,15 @@
 }
 #b, #c {
  display: inline-block;
- height: 20px; width: 200px;
+ height: 2em; width: 200px;
  background-color: blue;
  vertical-align: bottom;
 }
 #b {
- margin-bottom: 10px;
+ margin-bottom: 1em;
 }
 #c {
- margin-top: 10px;
+ margin-top: 1em;
 }
 </style>
 </head>
diff --git a/layout/reftests/marquee/413027-4-ref.html b/layout/reftests/marquee/413027-4-ref.html
index 50e14e729798..22fdd42e6016 100644
--- a/layout/reftests/marquee/413027-4-ref.html
+++ b/layout/reftests/marquee/413027-4-ref.html
@@ -4,7 +4,7 @@
 <body>
 
 <div style="background-color: lime; width: 600px; float:left;">
-  <div style="margin: 100px 0px;">text</div>
+  <div style="margin: 100px 0px; padding-left: 2px;">text</div>
 </div>
       
 </body></html>
diff --git a/layout/reftests/marquee/413027-4.html b/layout/reftests/marquee/413027-4.html
index 7e5e9379f3c4..d57f2f121517 100644
--- a/layout/reftests/marquee/413027-4.html
+++ b/layout/reftests/marquee/413027-4.html
@@ -5,7 +5,10 @@
 
 <marquee scrollamount="0" behavior="alternate" direction="right" style="background-color: lime; width: 600px;">
 <div>
-  <div style="margin: 100px 0px;">text</div>
+<!-- padding-left used to avoid risk of an antialiasing pixel that may
+     project to the left of the origin, causing a spurious test failure
+     (see bugs 476927, 475968) -->
+  <div style="margin: 100px 0px; padding-left: 2px;">text</div>
 </div>
 </marquee>
       
diff --git a/layout/reftests/pagination/content-inserted-000.ref.xhtml b/layout/reftests/pagination/content-inserted-000.ref.xhtml
index 7bef4dfef1ec..b3037746a50b 100644
--- a/layout/reftests/pagination/content-inserted-000.ref.xhtml
+++ b/layout/reftests/pagination/content-inserted-000.ref.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in {ib} Pagination with Overflow Containers</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 400px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-000.xhtml b/layout/reftests/pagination/content-inserted-000.xhtml
index d266a775fd2c..328bdf9160e5 100644
--- a/layout/reftests/pagination/content-inserted-000.xhtml
+++ b/layout/reftests/pagination/content-inserted-000.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in {ib} Pagination with Overflow Containers</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 400px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-001.ref.xhtml b/layout/reftests/pagination/content-inserted-001.ref.xhtml
index 078ca74b7cb5..358aef640125 100644
--- a/layout/reftests/pagination/content-inserted-001.ref.xhtml
+++ b/layout/reftests/pagination/content-inserted-001.ref.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Paginated Element</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-001.xhtml b/layout/reftests/pagination/content-inserted-001.xhtml
index 2fdbb4a62ab0..6ea28ae1012a 100644
--- a/layout/reftests/pagination/content-inserted-001.xhtml
+++ b/layout/reftests/pagination/content-inserted-001.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Paginated Element</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-002.ref.xhtml b/layout/reftests/pagination/content-inserted-002.ref.xhtml
index 37bded68a1b4..a2a4f77afa7a 100644
--- a/layout/reftests/pagination/content-inserted-002.ref.xhtml
+++ b/layout/reftests/pagination/content-inserted-002.ref.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-002.xhtml b/layout/reftests/pagination/content-inserted-002.xhtml
index 26ece6d1f198..f5907f639905 100644
--- a/layout/reftests/pagination/content-inserted-002.xhtml
+++ b/layout/reftests/pagination/content-inserted-002.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination before ::after</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-003.xhtml b/layout/reftests/pagination/content-inserted-003.xhtml
index 636a67971a06..913b82646f2a 100644
--- a/layout/reftests/pagination/content-inserted-003.xhtml
+++ b/layout/reftests/pagination/content-inserted-003.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination before ::after (alternate)</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-004.xhtml b/layout/reftests/pagination/content-inserted-004.xhtml
index aaf797a30e9f..2148be98776e 100644
--- a/layout/reftests/pagination/content-inserted-004.xhtml
+++ b/layout/reftests/pagination/content-inserted-004.xhtml
@@ -4,6 +4,10 @@
   <title>Content Inserted in Pagination after ::before</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-005.xhtml b/layout/reftests/pagination/content-inserted-005.xhtml
index de0c6532e349..f83f4d43311b 100644
--- a/layout/reftests/pagination/content-inserted-005.xhtml
+++ b/layout/reftests/pagination/content-inserted-005.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination after ::before</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-006.xhtml b/layout/reftests/pagination/content-inserted-006.xhtml
index 834e69746804..513638577d4f 100644
--- a/layout/reftests/pagination/content-inserted-006.xhtml
+++ b/layout/reftests/pagination/content-inserted-006.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination before ::after (alternate)</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-007.xhtml b/layout/reftests/pagination/content-inserted-007.xhtml
index c6ee648251a6..f7e217914cb0 100644
--- a/layout/reftests/pagination/content-inserted-007.xhtml
+++ b/layout/reftests/pagination/content-inserted-007.xhtml
@@ -4,6 +4,10 @@
   <title>Content Inserted in Pagination after ::before</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-008.xhtml b/layout/reftests/pagination/content-inserted-008.xhtml
index 854e5faa3f69..621683d9924f 100644
--- a/layout/reftests/pagination/content-inserted-008.xhtml
+++ b/layout/reftests/pagination/content-inserted-008.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination before ::after</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/content-inserted-009.xhtml b/layout/reftests/pagination/content-inserted-009.xhtml
index cc343bb01184..031b27217b94 100644
--- a/layout/reftests/pagination/content-inserted-009.xhtml
+++ b/layout/reftests/pagination/content-inserted-009.xhtml
@@ -4,6 +4,10 @@
   <title>Content Appended in Pagination before ::after</title>
 
   <style type="text/css">
+    body {
+      font-size: 16px;
+    }
+
     #colset {
       height: 200px;
       width: 450px;
diff --git a/layout/reftests/pagination/resize-reflow-001.inner.html b/layout/reftests/pagination/resize-reflow-001.inner.html
index 91130ff868cc..11647d26abe8 100644
--- a/layout/reftests/pagination/resize-reflow-001.inner.html
+++ b/layout/reftests/pagination/resize-reflow-001.inner.html
@@ -11,7 +11,7 @@
 
 <div style="-moz-column-width: 12em;
             border: silver solid;
-            height: 3em;">
+            height: 4em;">
   <div style="border: dotted;
               background: aqua;
               color: gray;">
diff --git a/layout/reftests/pagination/resize-reflow-001.ref.html b/layout/reftests/pagination/resize-reflow-001.ref.html
index b35efa7c0a90..625076d5af57 100644
--- a/layout/reftests/pagination/resize-reflow-001.ref.html
+++ b/layout/reftests/pagination/resize-reflow-001.ref.html
@@ -7,7 +7,7 @@
 
 <div style="-moz-column-width: 12em;
             border: silver solid;
-            height: 3em;">
+            height: 4em;">
   <div style="border: dotted;
               background: aqua;
               color: gray;">
