From 45b95898e05c4ff152f41642f31d5ccbf6e2fd6c Mon Sep 17 00:00:00 2001
From: Ryan VanderMeulen <ryanvm@gmail.com>
Date: Fri, 29 May 2015 12:48:22 -0400
Subject: [PATCH] Backed out changeset 541cd29ea626 (bug 1166728) because the
 updated patch wasn't posted to the bug.

---
 .../content/aboutPrivateBrowsing.css          |  2 +-
 browser/themes/linux/searchbar.css            |  2 +-
 browser/themes/osx/searchbar.css              |  2 +-
 browser/themes/shared/aboutNetError.css       |  2 +-
 browser/themes/windows/searchbar.css          |  2 +-
 dom/base/test/test_bug320799.html             |  2 +-
 layout/base/nsLayoutUtils.cpp                 | 28 +++++++++--
 layout/forms/test/test_textarea_resize.html   |  2 +-
 layout/generic/nsFrame.cpp                    |  8 ++-
 layout/generic/nsHTMLReflowState.cpp          | 26 +++++++---
 .../box-properties/box-sizing-1-ref.html      | 12 +++++
 .../reftests/box-properties/box-sizing-1.html | 13 +++++
 .../box-properties/box-sizing-2-ref.html      | 11 +++++
 .../reftests/box-properties/box-sizing-2.html | 12 +++++
 .../reftests/box-properties/box-sizing-3.html | 13 +++++
 .../box-properties/box-sizing-4-ref.html      | 12 +++++
 .../reftests/box-properties/box-sizing-4.html | 13 +++++
 .../box-sizing-mozbox-minmax-height-ref.html  |  5 ++
 .../box-sizing-mozbox-minmax-height.html      | 10 ++++
 .../computed-size-reporting-ref.html          | 12 +++++
 .../box-sizing/computed-size-reporting.html   | 13 +++++
 layout/reftests/box-sizing/intrinsic-1a.html  |  2 +-
 layout/reftests/box-sizing/intrinsic-1b.html  |  2 +-
 layout/reftests/box-sizing/intrinsic-1d.html  |  2 +-
 layout/reftests/box-sizing/intrinsic-1e.html  |  2 +-
 layout/reftests/box-sizing/intrinsic-1f.html  |  2 +-
 .../ui3/box-sizing-padding-box-001-ref.xht    | 40 +++++++++++++++
 .../ui3/box-sizing-padding-box-001.xht        | 43 ++++++++++++++++
 .../ui3/box-sizing-padding-box-002-ref.xht    | 42 ++++++++++++++++
 .../ui3/box-sizing-padding-box-002.xht        | 45 +++++++++++++++++
 .../ui3/box-sizing-padding-box-003-ref.xht    | 42 ++++++++++++++++
 .../ui3/box-sizing-padding-box-003.xht        | 49 +++++++++++++++++++
 .../submitted/ui3/box-sizing-replaced-001.xht |  2 +-
 .../w3c-css/submitted/ui3/reftest.list        |  3 ++
 layout/style/nsCSSProps.cpp                   |  1 +
 layout/style/nsComputedDOMStyle.cpp           |  9 +++-
 layout/style/nsStyleConsts.h                  |  3 +-
 layout/style/test/property_database.js        |  8 +--
 layout/tables/BasicTableLayoutStrategy.cpp    | 20 ++++++--
 layout/tables/FixedTableLayoutStrategy.cpp    | 14 +++++-
 layout/tables/nsTableRowFrame.cpp             | 12 ++++-
 layout/xul/nsResizerFrame.cpp                 |  9 +++-
 .../shared/in-content/info-pages.inc.css      |  2 +-
 43 files changed, 514 insertions(+), 42 deletions(-)
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001-ref.xht
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001.xht
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002-ref.xht
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002.xht
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003-ref.xht
 create mode 100644 layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003.xht

diff --git a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css
index 6283c2781beb..ca0ab3f035d3 100644
--- a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css
+++ b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css
@@ -8,7 +8,7 @@
 
 body {
   display: flex;
-  box-sizing: border-box;
+  box-sizing: padding-box;
   min-height: 100vh;
   padding: 0 48px;
   align-items: center;
diff --git a/browser/themes/linux/searchbar.css b/browser/themes/linux/searchbar.css
index 4627bbad4ec1..f293c4253db3 100644
--- a/browser/themes/linux/searchbar.css
+++ b/browser/themes/linux/searchbar.css
@@ -168,7 +168,7 @@ searchbar[oneoffui] .search-go-button:-moz-locale-dir(rtl) > .toolbarbutton-icon
 }
 
 .searchbar-engine-one-off-item:not(.last-row) {
-  box-sizing: content-box;
+  box-sizing: padding-box;
   border-bottom: 1px solid #ccc;
 }
 
diff --git a/browser/themes/osx/searchbar.css b/browser/themes/osx/searchbar.css
index f8fb109aea9a..b4075afc66d1 100644
--- a/browser/themes/osx/searchbar.css
+++ b/browser/themes/osx/searchbar.css
@@ -191,7 +191,7 @@ searchbar[oneoffui] .search-go-button:-moz-locale-dir(rtl) > .toolbarbutton-icon
 }
 
 .searchbar-engine-one-off-item:not(.last-row) {
-  box-sizing: content-box;
+  box-sizing: padding-box;
   border-bottom: 1px solid #ccc;
 }
 
diff --git a/browser/themes/shared/aboutNetError.css b/browser/themes/shared/aboutNetError.css
index ebde91c660ff..3fce69f0e450 100644
--- a/browser/themes/shared/aboutNetError.css
+++ b/browser/themes/shared/aboutNetError.css
@@ -6,7 +6,7 @@
 
 body {
   display: flex;
-  box-sizing: border-box;
+  box-sizing: padding-box;
   min-height: 100vh;
   padding: 0 48px;
   align-items: center;
diff --git a/browser/themes/windows/searchbar.css b/browser/themes/windows/searchbar.css
index 931457d8243d..c2dde6df2944 100644
--- a/browser/themes/windows/searchbar.css
+++ b/browser/themes/windows/searchbar.css
@@ -225,7 +225,7 @@ searchbar[oneoffui] .search-go-button:-moz-locale-dir(rtl) > .toolbarbutton-icon
 }
 
 .searchbar-engine-one-off-item:not(.last-row) {
-  box-sizing: content-box;
+  box-sizing: padding-box;
   border-bottom: 1px solid #ccc;
 }
 
diff --git a/dom/base/test/test_bug320799.html b/dom/base/test/test_bug320799.html
index fd966dfb8606..c160283aba38 100644
--- a/dom/base/test/test_bug320799.html
+++ b/dom/base/test/test_bug320799.html
@@ -11,7 +11,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=320799
 <body>
 <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=320799">Mozilla Bug 320799</a>
 <p id="display">
-  <select id="s" style="width: 100px; box-sizing: content-box; border: 0">
+  <select id="s" style="width: 100px; box-sizing: padding-box">
     <option>This is a test, it really is a test I tell you</option>
   </select>
   <select id="s2">
diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
index 1409499d390a..aedd782e4aed 100644
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -4408,11 +4408,15 @@ nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,
 
       if (ratio.BSize(wm) != 0) {
         nscoord bSizeTakenByBoxSizing = 0;
-        if (boxSizing == NS_STYLE_BOX_SIZING_BORDER) {
+        switch (boxSizing) {
+        case NS_STYLE_BOX_SIZING_BORDER: {
           const nsStyleBorder* styleBorder = aFrame->StyleBorder();
           bSizeTakenByBoxSizing +=
             wm.IsVertical() ? styleBorder->GetComputedBorder().LeftRight()
                             : styleBorder->GetComputedBorder().TopBottom();
+          // fall through
+        }
+        case NS_STYLE_BOX_SIZING_PADDING: {
           if (!(aFlags & IGNORE_PADDING)) {
             const nsStyleSides& stylePadding =
               aFrame->StylePadding()->mPadding;
@@ -4428,6 +4432,11 @@ nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,
               bSizeTakenByBoxSizing += pad;
             }
           }
+          // fall through
+        }
+        case NS_STYLE_BOX_SIZING_CONTENT:
+        default:
+          break;
         }
 
         nscoord h;
@@ -4476,6 +4485,15 @@ nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,
   if (!(aFlags & IGNORE_PADDING)) {
     coordOutsideISize += offsets.hPadding;
     pctOutsideISize += offsets.hPctPadding;
+
+    if (boxSizing == NS_STYLE_BOX_SIZING_PADDING) {
+      min += coordOutsideISize;
+      result = NSCoordSaturatingAdd(result, coordOutsideISize);
+      pctTotal += pctOutsideISize;
+
+      coordOutsideISize = 0;
+      pctOutsideISize = 0.0f;
+    }
   }
 
   coordOutsideISize += offsets.hBorder;
@@ -4786,8 +4804,12 @@ nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(WritingMode aWM,
   const bool isAutoBSize = IsAutoBSize(*blockStyleCoord, aCBSize.BSize(aWM));
 
   LogicalSize boxSizingAdjust(aWM);
-  if (stylePos->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    boxSizingAdjust += aBorder + aPadding;
+  switch (stylePos->mBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      boxSizingAdjust += aBorder;
+      // fall through
+    case NS_STYLE_BOX_SIZING_PADDING:
+      boxSizingAdjust += aPadding;
   }
   nscoord boxSizingToMarginEdgeISize =
     aMargin.ISize(aWM) + aBorder.ISize(aWM) + aPadding.ISize(aWM) -
diff --git a/layout/forms/test/test_textarea_resize.html b/layout/forms/test/test_textarea_resize.html
index 5761b1f9d50d..78b06d4097f6 100644
--- a/layout/forms/test/test_textarea_resize.html
+++ b/layout/forms/test/test_textarea_resize.html
@@ -25,7 +25,7 @@ var currentResize = -1;
 var currentBoxSizing = 0;
 var currentPointer = 0;
 var resizeTypes = [ "horizontal", "vertical", "none", "inherit", "both" ];
-var boxSizingTypes = [ "", "border-box" ];
+var boxSizingTypes = [ "", "border-box", "padding-box" ];
 var pointerTypes = [ synthesizeMouse, synthesizeTouch]
 
 function doTheTest() {
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index 62cc01dab8b3..30b2aebc4a64 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -4180,8 +4180,12 @@ nsFrame::ComputeSize(nsRenderingContext *aRenderingContext,
   LogicalSize boxSizingAdjust(aWM);
   const nsStylePosition *stylePos = StylePosition();
 
-  if (stylePos->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    boxSizingAdjust += aBorder + aPadding;
+  switch (stylePos->mBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      boxSizingAdjust += aBorder;
+      // fall through
+    case NS_STYLE_BOX_SIZING_PADDING:
+      boxSizingAdjust += aPadding;
   }
   nscoord boxSizingToMarginEdgeISize =
     aMargin.ISize(aWM) + aBorder.ISize(aWM) + aPadding.ISize(aWM) -
diff --git a/layout/generic/nsHTMLReflowState.cpp b/layout/generic/nsHTMLReflowState.cpp
index 32314dc9e7a0..070f36caf9fe 100644
--- a/layout/generic/nsHTMLReflowState.cpp
+++ b/layout/generic/nsHTMLReflowState.cpp
@@ -255,8 +255,13 @@ nsCSSOffsetState::ComputeWidthValue(nscoord aContainingBlockWidth,
 {
   nscoord inside = 0, outside = ComputedPhysicalBorderPadding().LeftRight() +
                                 ComputedPhysicalMargin().LeftRight();
-  if (aBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    inside = ComputedPhysicalBorderPadding().LeftRight();
+  switch (aBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      inside = ComputedPhysicalBorderPadding().LeftRight();
+      break;
+    case NS_STYLE_BOX_SIZING_PADDING:
+      inside = ComputedPhysicalPadding().LeftRight();
+      break;
   }
   outside -= inside;
 
@@ -270,8 +275,13 @@ nsCSSOffsetState::ComputeHeightValue(nscoord aContainingBlockHeight,
                                      const nsStyleCoord& aCoord)
 {
   nscoord inside = 0;
-  if (aBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    inside = ComputedPhysicalBorderPadding().TopBottom();
+  switch (aBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      inside = ComputedPhysicalBorderPadding().TopBottom();
+      break;
+    case NS_STYLE_BOX_SIZING_PADDING:
+      inside = ComputedPhysicalPadding().TopBottom();
+      break;
   }
   return nsLayoutUtils::ComputeHeightValue(aContainingBlockHeight, 
                                            inside, aCoord);
@@ -1086,8 +1096,12 @@ nsHTMLReflowState::CalculateHorizBorderPaddingMargin(
   nscoord outside =
     padding.LeftRight() + border.LeftRight() + margin.LeftRight();
   nscoord inside = 0;
-  if (mStylePosition->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    inside += border.LeftRight() + padding.LeftRight();
+  switch (mStylePosition->mBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      inside += border.LeftRight();
+      // fall through
+    case NS_STYLE_BOX_SIZING_PADDING:
+      inside += padding.LeftRight();
   }
   outside -= inside;
   *aInsideBoxSizing = inside;
diff --git a/layout/reftests/box-properties/box-sizing-1-ref.html b/layout/reftests/box-properties/box-sizing-1-ref.html
index 42aee1771916..f2caba6be740 100644
--- a/layout/reftests/box-properties/box-sizing-1-ref.html
+++ b/layout/reftests/box-properties/box-sizing-1-ref.html
@@ -46,6 +46,18 @@
 
 </div></td>
 
+<td id="bspadding"><div>
+<!-- box-sizing: padding-box -->
+<div style="width: 37px">A B</div>
+<div style="width: auto">A B</div>
+<div style="width: auto">A<br>B</div>
+<div style="width: auto">A B</div>
+<div style="width: 37px">A B</div>
+<div style="width: 38px">A B</div>
+<div style="width: 48px">A B</div>
+
+</div></td>
+
 <td id="bsborder"><div>
 <!-- box-sizing: border-box -->
 <div style="width: 37px">A B</div>
diff --git a/layout/reftests/box-properties/box-sizing-1.html b/layout/reftests/box-properties/box-sizing-1.html
index 83c9c1d0165c..21653296cb90 100644
--- a/layout/reftests/box-properties/box-sizing-1.html
+++ b/layout/reftests/box-properties/box-sizing-1.html
@@ -13,6 +13,7 @@
     td > div { width: 100px; }
 
     td#bscontent > div > div { box-sizing: content-box; }
+    td#bspadding > div > div { box-sizing: padding-box; }
     td#bsborder > div > div { box-sizing: border-box; }
 
     td > div > div {
@@ -46,6 +47,18 @@
 
 </div></td>
 
+<td id="bspadding"><div>
+<!-- box-sizing: padding-box -->
+<div style="width: auto">A B</div>
+<div style="width: -moz-max-content">A B</div>
+<div style="width: -moz-min-content">A B</div>
+<div style="width: -moz-fit-content">A B</div>
+<div style="width: -moz-available">A B</div>
+<div style="width: 50px">A B</div>
+<div style="width: 60%">A B</div>
+
+</div></td>
+
 <td id="bsborder"><div>
 <!-- box-sizing: border-box -->
 <div style="width: auto">A B</div>
diff --git a/layout/reftests/box-properties/box-sizing-2-ref.html b/layout/reftests/box-properties/box-sizing-2-ref.html
index b11313ed4e77..159c446d7ffe 100644
--- a/layout/reftests/box-properties/box-sizing-2-ref.html
+++ b/layout/reftests/box-properties/box-sizing-2-ref.html
@@ -39,6 +39,17 @@
 
 </td>
 
+<td id="bspadding">
+<!-- box-sizing: padding-box -->
+<table><tr><td><div>A B</div></td></tr></table>
+<table><tr><td><div>A B</div></td></tr></table>
+<table><tr><td><div>A<br>B</div></td></tr></table>
+<table><tr><td><div>A B</div></td></tr></table>
+<table><tr><td><div>A B</div></td></tr></table>
+<table><tr><td><div style="width: 138px">A B</div></td></tr></table>
+
+</td>
+
 <td id="bsborder">
 <!-- box-sizing: border-box -->
 <table><tr><td><div>A B</div></td></tr></table>
diff --git a/layout/reftests/box-properties/box-sizing-2.html b/layout/reftests/box-properties/box-sizing-2.html
index d61d8184f2d3..65585b091d3b 100644
--- a/layout/reftests/box-properties/box-sizing-2.html
+++ b/layout/reftests/box-properties/box-sizing-2.html
@@ -11,6 +11,7 @@
     td { border: 1px solid; padding: 1px solid; }
 
     td#bscontent td > div { box-sizing: content-box; }
+    td#bspadding td > div { box-sizing: padding-box; }
     td#bsborder td > div { box-sizing: border-box; }
 
     td td > div {
@@ -42,6 +43,17 @@
 
 </td>
 
+<td id="bspadding">
+<!-- box-sizing: padding-box -->
+<table><tr><td><div style="width: auto">A B</div></td></tr></table>
+<table><tr><td><div style="width: -moz-max-content">A B</div></td></tr></table>
+<table><tr><td><div style="width: -moz-min-content">A B</div></td></tr></table>
+<table><tr><td><div style="width: -moz-fit-content">A B</div></td></tr></table>
+<table><tr><td><div style="width: -moz-available">A B</div></td></tr></table>
+<table><tr><td><div style="width: 150px">A B</div></td></tr></table>
+
+</td>
+
 <td id="bsborder">
 <!-- box-sizing: border-box -->
 <table><tr><td><div style="width: auto">A B</div></td></tr></table>
diff --git a/layout/reftests/box-properties/box-sizing-3.html b/layout/reftests/box-properties/box-sizing-3.html
index dd4391d4c065..30f38884fde8 100644
--- a/layout/reftests/box-properties/box-sizing-3.html
+++ b/layout/reftests/box-properties/box-sizing-3.html
@@ -13,6 +13,7 @@
     td > div { width: 100px; }
 
     td#bscontent > div > div { box-sizing: content-box; }
+    td#bspadding > div > div { box-sizing: padding-box; }
     td#bsborder > div > div { box-sizing: border-box; }
 
     td > div > div {
@@ -46,6 +47,18 @@
 
 </div></td>
 
+<td id="bspadding"><div>
+<!-- box-sizing: padding-box -->
+<div style="width: auto">A B</div>
+<div style="width: -moz-max-content">A B</div>
+<div style="width: -moz-min-content">A B</div>
+<div style="width: -moz-fit-content">A B</div>
+<div style="width: -moz-available">A B</div>
+<div style="width: 50px">A B</div>
+<div style="width: 60%">A B</div>
+
+</div></td>
+
 <td id="bsborder"><div>
 <!-- box-sizing: border-box -->
 <div style="width: auto">A B</div>
diff --git a/layout/reftests/box-properties/box-sizing-4-ref.html b/layout/reftests/box-properties/box-sizing-4-ref.html
index b2a149dbe8d6..47a438775eaf 100644
--- a/layout/reftests/box-properties/box-sizing-4-ref.html
+++ b/layout/reftests/box-properties/box-sizing-4-ref.html
@@ -48,6 +48,18 @@
 
 </div></td>
 
+<td id="bspadding"><div>
+<!-- box-sizing: padding-box -->
+<div>A B</div>
+<div>A B</div>
+<div>A<br>B</div>
+<div>A B</div>
+<div style="width: 37px">A B</div>
+<div style="width: 38px">A B</div>
+<div style="width: 48px">A B</div>
+
+</div></td>
+
 <td id="bsborder"><div>
 <!-- box-sizing: border-box -->
 <div>A B</div>
diff --git a/layout/reftests/box-properties/box-sizing-4.html b/layout/reftests/box-properties/box-sizing-4.html
index f02eb12924e0..8622508c99a9 100644
--- a/layout/reftests/box-properties/box-sizing-4.html
+++ b/layout/reftests/box-properties/box-sizing-4.html
@@ -14,6 +14,7 @@
                direction: rtl; position: relative; }
 
     td#bscontent > div > div { box-sizing: content-box; }
+    td#bspadding > div > div { box-sizing: padding-box; }
     td#bsborder > div > div { box-sizing: border-box; }
 
     td > div > div {
@@ -58,6 +59,18 @@
 
 </div></td>
 
+<td id="bspadding"><div>
+<!-- box-sizing: padding-box -->
+<div style="width: auto">A B</div>
+<div style="width: -moz-max-content">A B</div>
+<div style="width: -moz-min-content">A B</div>
+<div style="width: -moz-fit-content">A B</div>
+<div style="width: -moz-available">A B</div>
+<div style="width: 50px">A B</div>
+<div style="width: 60%">A B</div>
+
+</div></td>
+
 <td id="bsborder"><div>
 <!-- box-sizing: border-box -->
 <div style="width: auto">A B</div>
diff --git a/layout/reftests/box-properties/box-sizing-mozbox-minmax-height-ref.html b/layout/reftests/box-properties/box-sizing-mozbox-minmax-height-ref.html
index 71b19db8c749..26f7be165000 100644
--- a/layout/reftests/box-properties/box-sizing-mozbox-minmax-height-ref.html
+++ b/layout/reftests/box-properties/box-sizing-mozbox-minmax-height-ref.html
@@ -43,5 +43,10 @@ hbox {
 <div><hbox class="cb" style="height:29px;">content-box 20px</hbox></div>
 
 
+<div><hbox class="pb" style="height:16px;">padding-box 20px</hbox></div>
+<div><hbox class="pb" style="height:46px;">padding-box 50px</hbox></div>
+<div><hbox class="pb" style="height:16px;">padding-box 20px</hbox></div>
+
+
 </body>
 </html>
diff --git a/layout/reftests/box-properties/box-sizing-mozbox-minmax-height.html b/layout/reftests/box-properties/box-sizing-mozbox-minmax-height.html
index df4d8c503fcd..b050bf13501f 100644
--- a/layout/reftests/box-properties/box-sizing-mozbox-minmax-height.html
+++ b/layout/reftests/box-properties/box-sizing-mozbox-minmax-height.html
@@ -25,6 +25,11 @@ hbox {
   background:pink;
 }
 
+.pb {
+  box-sizing:padding-box;
+  background:cyan;
+}
+
     </style>
 </head>
 <body>
@@ -39,5 +44,10 @@ hbox {
 <div><hbox class="cb" style="max-height:20px;">content-box 20px</hbox></div>
 
 
+<div><hbox class="pb" style="height:20px;">padding-box 20px</hbox></div>
+<div><hbox class="pb" style="min-height:50px;">padding-box 50px</hbox></div>
+<div><hbox class="pb" style="max-height:20px;">padding-box 20px</hbox></div>
+
+
 </body>
 </html>
diff --git a/layout/reftests/box-sizing/computed-size-reporting-ref.html b/layout/reftests/box-sizing/computed-size-reporting-ref.html
index f910417e596c..0784b309e0fe 100644
--- a/layout/reftests/box-sizing/computed-size-reporting-ref.html
+++ b/layout/reftests/box-sizing/computed-size-reporting-ref.html
@@ -9,14 +9,26 @@
     box-sizing:border-box;
   }
 
+  #paddingBox {
+    background:gold;
+    height:100px;
+    box-sizing:padding-box;
+  }
+
 </style>
 
 <div id="borderBox"></div>
 <p id="heightWidth1"></p>
 
+<div id="paddingBox"></div>
+<p id="heightWidth2"></p>
 <script>
   var divs = document.getElementsByTagName("div");
   var textEle1 = document.getElementById("heightWidth1");
   textEle1.innerHTML += "height = " + getComputedStyle(divs[0]).height;
   textEle1.innerHTML += ", width = " + getComputedStyle(divs[0]).width;
+
+  var textEle2 = document.getElementById("heightWidth2");
+  textEle2.innerHTML += "height = " + getComputedStyle(divs[1]).height;
+  textEle2.innerHTML += ", width = " + getComputedStyle(divs[1]).width;
 </script>
diff --git a/layout/reftests/box-sizing/computed-size-reporting.html b/layout/reftests/box-sizing/computed-size-reporting.html
index 227ea2cfbd26..fbcd62577a1f 100644
--- a/layout/reftests/box-sizing/computed-size-reporting.html
+++ b/layout/reftests/box-sizing/computed-size-reporting.html
@@ -10,14 +10,27 @@
     border: 20px solid gold;
   }
 
+  #paddingBox {
+    background:gold;
+    height:100px;
+    box-sizing:padding-box;
+    padding: 20px;
+  }
+
 </style>
 
 <div id="borderBox"></div>
 <p id="heightWidth1"></p>
 
+<div id="paddingBox"></div>
+<p id="heightWidth2"></p>
 <script>
   var divs = document.getElementsByTagName("div");
   var textEle1 = document.getElementById("heightWidth1");
   textEle1.innerHTML += "height = " + getComputedStyle(divs[0]).height;
   textEle1.innerHTML += ", width = " + getComputedStyle(divs[0]).width;
+
+  var textEle2 = document.getElementById("heightWidth2");
+  textEle2.innerHTML += "height = " + getComputedStyle(divs[1]).height;
+  textEle2.innerHTML += ", width = " + getComputedStyle(divs[1]).width;
 </script>
diff --git a/layout/reftests/box-sizing/intrinsic-1a.html b/layout/reftests/box-sizing/intrinsic-1a.html
index 2a678176dd1e..b2e7ebf46c6a 100644
--- a/layout/reftests/box-sizing/intrinsic-1a.html
+++ b/layout/reftests/box-sizing/intrinsic-1a.html
@@ -4,6 +4,6 @@
     <img src="lime100x100.png"
          style="height: 200px; display: block; visibility: hidden;
                 padding: 30px;
-                box-sizing: border-box;">
+                box-sizing: padding-box;">
   </div>
 </body>
diff --git a/layout/reftests/box-sizing/intrinsic-1b.html b/layout/reftests/box-sizing/intrinsic-1b.html
index 0bb5af75f310..398b2e37a8db 100644
--- a/layout/reftests/box-sizing/intrinsic-1b.html
+++ b/layout/reftests/box-sizing/intrinsic-1b.html
@@ -4,6 +4,6 @@
     <img src="lime100x100.png"
          style="height: 200px; display: block; visibility: hidden;
                 padding: 15% 30px;
-                box-sizing: border-box;">
+                box-sizing: padding-box;">
   </div>
 </body>
diff --git a/layout/reftests/box-sizing/intrinsic-1d.html b/layout/reftests/box-sizing/intrinsic-1d.html
index 08a982ff0ca1..6865d0b499c3 100644
--- a/layout/reftests/box-sizing/intrinsic-1d.html
+++ b/layout/reftests/box-sizing/intrinsic-1d.html
@@ -4,6 +4,6 @@
     <img src="lime100x100.png"
          style="height: 200px; display: block; visibility: hidden;
                 padding: calc(15%) 30px;
-                box-sizing: border-box;">
+                box-sizing: padding-box;">
   </div>
 </body>
diff --git a/layout/reftests/box-sizing/intrinsic-1e.html b/layout/reftests/box-sizing/intrinsic-1e.html
index c27cab66a1d3..3b35b67544d5 100644
--- a/layout/reftests/box-sizing/intrinsic-1e.html
+++ b/layout/reftests/box-sizing/intrinsic-1e.html
@@ -4,6 +4,6 @@
     <img src="lime100x100.png"
          style="height: 200px; display: block; visibility: hidden;
                 padding: calc(10% + 10px) 30px;
-                box-sizing: border-box;">
+                box-sizing: padding-box;">
   </div>
 </body>
diff --git a/layout/reftests/box-sizing/intrinsic-1f.html b/layout/reftests/box-sizing/intrinsic-1f.html
index a273761ab5de..6301127267ae 100644
--- a/layout/reftests/box-sizing/intrinsic-1f.html
+++ b/layout/reftests/box-sizing/intrinsic-1f.html
@@ -4,6 +4,6 @@
     <img src="lime100x100.png"
          style="height: 200px; display: block; visibility: hidden;
                 padding: calc(30px);
-                box-sizing: border-box;">
+                box-sizing: padding-box;">
   </div>
 </body>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001-ref.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001-ref.xht
new file mode 100644
index 000000000000..d9a1f41e4cc4
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001-ref.xht
@@ -0,0 +1,40 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Reference: Box Sizing - Padding-Box with specified width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <style type="text/css"><![CDATA[
+    .container {
+      width: 300px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      width: 140px;
+      z-index: 1;
+      float: left;
+      padding: 0px 5px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001.xht
new file mode 100644
index 000000000000..17f81850c393
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-001.xht
@@ -0,0 +1,43 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Test: Box Sizing - Padding-Box with specified width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <link rel="help" href="http://www.w3.org/TR/css3-ui/#box-sizing" />
+  <meta name="assert" content="box-sizing: padding-box should make the element's (percentage) width be the distance from the left padding edge to the right padding edge."/>
+  <style type="text/css"><![CDATA[
+    .container {
+      width: 300px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      box-sizing: padding-box;
+      width: 50%;
+      z-index: 1;
+      float: left;
+      padding: 0px 5px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002-ref.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002-ref.xht
new file mode 100644
index 000000000000..06260223d31d
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002-ref.xht
@@ -0,0 +1,42 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Reference: Box Sizing - Padding-Box with specified width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <style type="text/css"><![CDATA[
+    .container {
+      width: 300px;
+      height: 400px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      width: 130px;
+      height: 350px;
+      z-index: 1;
+      float: left;
+      padding: 25px 10px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002.xht
new file mode 100644
index 000000000000..282e2be72b1c
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-002.xht
@@ -0,0 +1,45 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Test: Box Sizing - Padding-Box with specified width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <link rel="help" href="http://www.w3.org/TR/css3-ui/#box-sizing" />
+  <meta name="assert" content="box-sizing: padding-box should make the element's (percentage) width be the distance from the left padding edge to the right padding edge and the height be the distance from the top padding edge to the bottom padding edge."/>
+  <style type="text/css"><![CDATA[
+    .container {
+      width: 300px;
+      height: 400px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      box-sizing: padding-box;
+      width: 50%;
+      height: 100%;
+      z-index: 1;
+      float: left;
+      padding: 25px 10px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003-ref.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003-ref.xht
new file mode 100644
index 000000000000..d3ba96f37e4f
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003-ref.xht
@@ -0,0 +1,42 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Reference: Box Sizing - Padding-Box with min/max width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <style type="text/css"><![CDATA[
+    .container {
+      width: 500px;
+      height: 70px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      height: calc(100% - 10px);
+      width: calc(50% - 10px);
+      z-index: 1;
+      float: left;
+      padding: 5px 5px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003.xht
new file mode 100644
index 000000000000..79d7e3add9cf
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-padding-box-003.xht
@@ -0,0 +1,49 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+ <head>
+  <title>CSS Test: Box Sizing - Padding-Box with min/max width/height</title>
+  <link rel="author" title="Scott Johnson" href="mailto:sjohnson@mozilla.com" />
+  <link rel="help" href="http://www.w3.org/TR/css3-ui/#box-sizing" />
+  <meta name="assert" content="box-sizing: padding-box should make the element's (calc) width be the distance from the left padding edge to the right padding edge and the height be the distance from the top padding edge to the bottom padding edge."/>
+  <style type="text/css"><![CDATA[
+    .container {
+      min-width: 500px;
+      max-width: 700px;
+      min-height: 70px;
+      max-height: 90px;
+      border: 2px solid black;
+      position: absolute;
+      left: 25px;
+      top: 25px;
+      background-color: red;
+    }
+
+    .box-sized {
+      box-sizing: padding-box;
+      min-width: 250px;
+      max-width: 350px;
+      min-height: 70px;
+      max-height: 90px;
+      z-index: 1;
+      float: left;
+      padding: 5px 5px;
+    }
+
+    #one {
+      background-color: green;
+    }
+
+    #two {
+      background-color: blue;
+    }
+  ]]></style>
+ </head>
+ <body>
+   The two divs should be side-by-side, not one on top of another. No red should be visible.
+   <br />
+   <div class="container">
+     <div class="box-sized" id="one">LEFT HALF</div>
+     <div class="box-sized" id="two">RIGHT HALF</div>
+   </div>
+ </body>
+</html>
diff --git a/layout/reftests/w3c-css/submitted/ui3/box-sizing-replaced-001.xht b/layout/reftests/w3c-css/submitted/ui3/box-sizing-replaced-001.xht
index ad0e5086e171..3dd9dee390f9 100644
--- a/layout/reftests/w3c-css/submitted/ui3/box-sizing-replaced-001.xht
+++ b/layout/reftests/w3c-css/submitted/ui3/box-sizing-replaced-001.xht
@@ -21,7 +21,7 @@
 
       .with-padding {
         padding: 5px 5px;
-        box-sizing: border-box;
+        box-sizing: padding-box;
       }
 
       #img1 {
diff --git a/layout/reftests/w3c-css/submitted/ui3/reftest.list b/layout/reftests/w3c-css/submitted/ui3/reftest.list
index ccf2b9fb4fe2..40bc22686935 100644
--- a/layout/reftests/w3c-css/submitted/ui3/reftest.list
+++ b/layout/reftests/w3c-css/submitted/ui3/reftest.list
@@ -5,6 +5,9 @@
 == box-sizing-content-box-001.xht box-sizing-content-box-001-ref.xht
 == box-sizing-content-box-002.xht box-sizing-content-box-002-ref.xht
 == box-sizing-content-box-003.xht box-sizing-content-box-003-ref.xht
+== box-sizing-padding-box-001.xht box-sizing-padding-box-001-ref.xht
+== box-sizing-padding-box-002.xht box-sizing-padding-box-002-ref.xht
+== box-sizing-padding-box-003.xht box-sizing-padding-box-003-ref.xht
 random-if(Android) skip-if((B2G&&browserIsRemote)||Mulet)  == box-sizing-replaced-001.xht box-sizing-replaced-001-ref.xht #bug 982547 # Initial mulet triage: parity with B2G/B2G Desktop
 fuzzy-if(Android,27,874) random-if((B2G&&browserIsRemote)||Mulet) == box-sizing-replaced-002.xht box-sizing-replaced-002-ref.xht # Bug 1128229 # Initial mulet triage: parity with B2G/B2G Desktop
 fuzzy-if(Android,14,869) random-if((B2G&&browserIsRemote)||Mulet) == box-sizing-replaced-003.xht box-sizing-replaced-003-ref.xht # Bug 1128229 # Initial mulet triage: parity with B2G/B2G Desktop
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index 23d2ca93817e..5e97f82bea9a 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -888,6 +888,7 @@ const KTableValue nsCSSProps::kBoxShadowTypeKTable[] = {
 const KTableValue nsCSSProps::kBoxSizingKTable[] = {
   eCSSKeyword_content_box,  NS_STYLE_BOX_SIZING_CONTENT,
   eCSSKeyword_border_box,   NS_STYLE_BOX_SIZING_BORDER,
+  eCSSKeyword_padding_box,  NS_STYLE_BOX_SIZING_PADDING,
   eCSSKeyword_UNKNOWN,-1
 };
 
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 7352cfc823a0..4829f464b514 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -517,8 +517,13 @@ nsComputedDOMStyle::GetAdjustedValuesForBoxSizing()
   const nsStylePosition* stylePos = StylePosition();
 
   nsMargin adjustment;
-  if (stylePos->mBoxSizing == NS_STYLE_BOX_SIZING_BORDER) {
-    adjustment += mInnerFrame->GetUsedBorderAndPadding();
+  switch(stylePos->mBoxSizing) {
+    case NS_STYLE_BOX_SIZING_BORDER:
+      adjustment += mInnerFrame->GetUsedBorder();
+      // fall through
+
+    case NS_STYLE_BOX_SIZING_PADDING:
+      adjustment += mInnerFrame->GetUsedPadding();
   }
 
   return adjustment;
diff --git a/layout/style/nsStyleConsts.h b/layout/style/nsStyleConsts.h
index 1e769ccf398f..a9f326ce1f25 100644
--- a/layout/style/nsStyleConsts.h
+++ b/layout/style/nsStyleConsts.h
@@ -58,7 +58,8 @@ static inline mozilla::css::Side operator++(mozilla::css::Side& side, int) {
 
 // box-sizing
 #define NS_STYLE_BOX_SIZING_CONTENT       0
-#define NS_STYLE_BOX_SIZING_BORDER        1
+#define NS_STYLE_BOX_SIZING_PADDING       1
+#define NS_STYLE_BOX_SIZING_BORDER        2
 
 // clip-path sizing
 #define NS_STYLE_CLIP_SHAPE_SIZING_NOBOX   0
diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index 6a8645a9068d..2fe81023882f 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -1045,8 +1045,8 @@ var gCSSProperties = {
     inherited: false,
     type: CSS_TYPE_LONGHAND,
     initial_values: [ "content-box" ],
-    other_values: [ "border-box" ],
-    invalid_values: [ "margin-box", "content", "padding", "border", "margin", "padding-box" ]
+    other_values: [ "border-box", "padding-box" ],
+    invalid_values: [ "margin-box", "content", "padding", "border", "margin" ]
   },
   "-moz-box-sizing": {
     domProp: "MozBoxSizing",
@@ -1055,8 +1055,8 @@ var gCSSProperties = {
     alias_for: "box-sizing",
     subproperties: [ "box-sizing" ],
     initial_values: [ "content-box" ],
-    other_values: [ "border-box" ],
-    invalid_values: [ "margin-box", "content", "padding", "border", "margin", "padding-box" ]
+    other_values: [ "border-box", "padding-box" ],
+    invalid_values: [ "margin-box", "content", "padding", "border", "margin" ]
   },
   "-moz-columns": {
     domProp: "MozColumns",
diff --git a/layout/tables/BasicTableLayoutStrategy.cpp b/layout/tables/BasicTableLayoutStrategy.cpp
index fac125eaeb08..bd808034efbb 100644
--- a/layout/tables/BasicTableLayoutStrategy.cpp
+++ b/layout/tables/BasicTableLayoutStrategy.cpp
@@ -113,13 +113,25 @@ GetWidthInfo(nsRenderingContext *aRenderingContext,
         // for height).
         // For this reason, we also do not use box-sizing for just one of
         // them, as this may be confusing.
-        if (isQuirks || stylePos->mBoxSizing == NS_STYLE_BOX_SIZING_CONTENT) {
+        if (isQuirks) {
             boxSizingToBorderEdge = offsets.hPadding + offsets.hBorder;
         }
         else {
-            // NS_STYLE_BOX_SIZING_BORDER and standards-mode
-            minCoord += offsets.hPadding + offsets.hBorder;
-            prefCoord += offsets.hPadding + offsets.hBorder;
+            switch (stylePos->mBoxSizing) {
+                case NS_STYLE_BOX_SIZING_CONTENT:
+                    boxSizingToBorderEdge = offsets.hPadding + offsets.hBorder;
+                    break;
+                case NS_STYLE_BOX_SIZING_PADDING:
+                    minCoord += offsets.hPadding;
+                    prefCoord += offsets.hPadding;
+                    boxSizingToBorderEdge = offsets.hBorder;
+                    break;
+                default:
+                    // NS_STYLE_BOX_SIZING_BORDER
+                    minCoord += offsets.hPadding + offsets.hBorder;
+                    prefCoord += offsets.hPadding + offsets.hBorder;
+                    break;
+            }
         }
     } else {
         minCoord = 0;
diff --git a/layout/tables/FixedTableLayoutStrategy.cpp b/layout/tables/FixedTableLayoutStrategy.cpp
index e0dc4db7bd93..8a929fc3356c 100644
--- a/layout/tables/FixedTableLayoutStrategy.cpp
+++ b/layout/tables/FixedTableLayoutStrategy.cpp
@@ -252,9 +252,19 @@ FixedTableLayoutStrategy::ComputeColumnISizes(const nsHTMLReflowState& aReflowSt
                     float pct = styleWidth->GetPercentValue();
                     colWidth = NSToCoordFloor(pct * float(tableWidth));
 
-                    if (cellFrame->StylePosition()->mBoxSizing == NS_STYLE_BOX_SIZING_CONTENT) {
-                        colWidth += offsets.hPadding + offsets.hBorder;
+                    nscoord boxSizingAdjust = 0;
+                    switch (cellFrame->StylePosition()->mBoxSizing) {
+                      case NS_STYLE_BOX_SIZING_CONTENT:
+                        boxSizingAdjust += offsets.hPadding;
+                        // Fall through
+                      case NS_STYLE_BOX_SIZING_PADDING:
+                        boxSizingAdjust += offsets.hBorder;
+                        // Fall through
+                      case NS_STYLE_BOX_SIZING_BORDER:
+                        // Don't add anything
+                        break;
                     }
+                    colWidth += boxSizingAdjust;
 
                     pct /= float(colSpan);
                     colFrame->AddPrefPercent(pct);
diff --git a/layout/tables/nsTableRowFrame.cpp b/layout/tables/nsTableRowFrame.cpp
index 60a480f2f6d7..2f8dc8eabb5c 100644
--- a/layout/tables/nsTableRowFrame.cpp
+++ b/layout/tables/nsTableRowFrame.cpp
@@ -629,8 +629,16 @@ nsTableRowFrame::CalculateCellActualHeight(nsTableCellFrame* aCellFrame,
       // (since we can't specify one value of box-sizing for width and another
       // for height)
       if (PresContext()->CompatibilityMode() != eCompatibility_NavQuirks) {
-        if (position->mBoxSizing == NS_STYLE_BOX_SIZING_CONTENT) {
-          outsideBoxSizing = aCellFrame->GetUsedBorderAndPadding().TopBottom();
+        switch (position->mBoxSizing) {
+          case NS_STYLE_BOX_SIZING_CONTENT:
+            outsideBoxSizing = aCellFrame->GetUsedBorderAndPadding().TopBottom();
+            break;
+          case NS_STYLE_BOX_SIZING_PADDING:
+            outsideBoxSizing = aCellFrame->GetUsedBorder().TopBottom();
+            break;
+          default:
+            // NS_STYLE_BOX_SIZING_BORDER
+            break;
         }
       }
 
diff --git a/layout/xul/nsResizerFrame.cpp b/layout/xul/nsResizerFrame.cpp
index c77c30139ea3..ea353a7be0f0 100644
--- a/layout/xul/nsResizerFrame.cpp
+++ b/layout/xul/nsResizerFrame.cpp
@@ -80,8 +80,13 @@ nsResizerFrame::HandleEvent(nsPresContext* aPresContext,
           // GetScreenRectInAppUnits returns the border box rectangle, so
           // adjust to get the desired content rectangle.
           nsRect rect = frameToResize->GetScreenRectInAppUnits();
-          if (frameToResize->StylePosition()->mBoxSizing == NS_STYLE_BOX_SIZING_CONTENT) {
-            rect.Deflate(frameToResize->GetUsedBorderAndPadding());
+          switch (frameToResize->StylePosition()->mBoxSizing) {
+            case NS_STYLE_BOX_SIZING_CONTENT:
+              rect.Deflate(frameToResize->GetUsedPadding());
+            case NS_STYLE_BOX_SIZING_PADDING:
+              rect.Deflate(frameToResize->GetUsedBorder());
+            default:
+              break;
           }
 
           mMouseDownRect =
diff --git a/toolkit/themes/shared/in-content/info-pages.inc.css b/toolkit/themes/shared/in-content/info-pages.inc.css
index 13ecca2525e7..7d1a55377007 100644
--- a/toolkit/themes/shared/in-content/info-pages.inc.css
+++ b/toolkit/themes/shared/in-content/info-pages.inc.css
@@ -7,7 +7,7 @@
 body {
   display: flex;
   flex-direction: column;
-  box-sizing: border-box;
+  box-sizing: padding-box;
   min-height: 100vh;
   padding-top: 0;
   padding-bottom: 0;