diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
index 35c145abb498fa54caa2c827d9cf9fe0aa962dfc..e46ed972732f1fc52c63e67a200379357dbe9635 100644
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -153,7 +153,6 @@ using namespace mozilla::gfx;
#define GRID_ENABLED_PREF_NAME "layout.css.grid.enabled"
#define GRID_TEMPLATE_SUBGRID_ENABLED_PREF_NAME "layout.css.grid-template-subgrid-value.enabled"
#define WEBKIT_PREFIXES_ENABLED_PREF_NAME "layout.css.prefixes.webkit"
-#define DISPLAY_FLOW_ROOT_ENABLED_PREF_NAME "layout.css.display-flow-root.enabled"
#define TEXT_ALIGN_UNSAFE_ENABLED_PREF_NAME "layout.css.text-align-unsafe-value.enabled"
#define FLOAT_LOGICAL_VALUES_ENABLED_PREF_NAME "layout.css.float-logical-values.enabled"
@@ -320,36 +319,6 @@ WebkitPrefixEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)
}
}
-// When the pref "layout.css.display-flow-root.enabled" changes, this function is
-// invoked to let us update kDisplayKTable, to selectively disable or restore
-// the entries for "flow-root" in that table.
-static void
-DisplayFlowRootEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)
-{
- NS_ASSERTION(strcmp(aPrefName, DISPLAY_FLOW_ROOT_ENABLED_PREF_NAME) == 0,
- "Did you misspell " DISPLAY_FLOW_ROOT_ENABLED_PREF_NAME " ?");
-
- static bool sIsDisplayFlowRootKeywordIndexInitialized;
- static int32_t sIndexOfFlowRootInDisplayTable;
- bool isDisplayFlowRootEnabled =
- Preferences::GetBool(DISPLAY_FLOW_ROOT_ENABLED_PREF_NAME, false);
-
- if (!sIsDisplayFlowRootKeywordIndexInitialized) {
- // First run: find the position of "flow-root" in kDisplayKTable.
- sIndexOfFlowRootInDisplayTable =
- nsCSSProps::FindIndexOfKeyword(eCSSKeyword_flow_root,
- nsCSSProps::kDisplayKTable);
- sIsDisplayFlowRootKeywordIndexInitialized = true;
- }
-
- // OK -- now, stomp on or restore the "flow-root" entry in kDisplayKTable,
- // depending on whether the pref is enabled vs. disabled.
- if (sIndexOfFlowRootInDisplayTable >= 0) {
- nsCSSProps::kDisplayKTable[sIndexOfFlowRootInDisplayTable].mKeyword =
- isDisplayFlowRootEnabled ? eCSSKeyword_flow_root : eCSSKeyword_UNKNOWN;
- }
-}
-
// When the pref "layout.css.text-align-unsafe-value.enabled" changes, this
// function is called to let us update kTextAlignKTable & kTextAlignLastKTable,
// to selectively disable or restore the entries for "unsafe" in those tables.
@@ -7780,8 +7749,6 @@ static const PrefCallbacks kPrefCallbacks[] = {
WebkitPrefixEnabledPrefChangeCallback },
{ TEXT_ALIGN_UNSAFE_ENABLED_PREF_NAME,
TextAlignUnsafeEnabledPrefChangeCallback },
- { DISPLAY_FLOW_ROOT_ENABLED_PREF_NAME,
- DisplayFlowRootEnabledPrefChangeCallback },
{ FLOAT_LOGICAL_VALUES_ENABLED_PREF_NAME,
FloatLogicalValuesEnabledPrefChangeCallback },
};
diff --git a/layout/reftests/css-display/display-flow-root-disabled-001-ref.html b/layout/reftests/css-display/display-flow-root-disabled-001-ref.html
deleted file mode 100644
index 15f99ceb0c6bccd89cf105f84cfe749e79d8d4cf..0000000000000000000000000000000000000000
--- a/layout/reftests/css-display/display-flow-root-disabled-001-ref.html
+++ /dev/null
@@ -1,51 +0,0 @@
-<!DOCTYPE HTML>
-<!--
- Any copyright is dedicated to the Public Domain.
- http://creativecommons.org/publicdomain/zero/1.0/
--->
-<html><head>
- <meta charset="utf-8">
- <title>Reference: display:flow-root (disabled)</title>
- <link rel="author" title="Mats Palmgren" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1322191">
- <style type="text/css">
-html,body {
- color:black; background-color:white; font:16px/1 monospace; padding:0; margin:0;
-}
-
-.float {
- float: left;
- width: 20px;
- height: 40px;
- background: pink;
-}
-
- </style>
-</head>
-<body>
-
-<div style="border:1px solid">
- <span>
- <div style="margin: 20px 0">x</div>
- </span>
-</div>
-
-<div style="border:1px solid">
- <span><div class="float"></div></span>
-</div>
-
-<div style="border:1px solid">
- <div class="float"></div>
- <span style="border:1px solid">x</span>
-</div>
-
-<span>
- <span style="display:inline-block; margin-top:20px"><div>x</div></span>
-</span>
-
-<div style="margin-top:20px"></div>
-<span style="border:3px solid; height:10px">
- <!-- this tests that a flow-root fills the available width, and that 'height' applies -->
-</span>
-
-</body>
-</html>
diff --git a/layout/reftests/css-display/reftest.list b/layout/reftests/css-display/reftest.list
index 60e97d3d9ca4252a3e17a07e33733bb326a8a264..d09842c55effc339824491709b988afde4215566 100644
--- a/layout/reftests/css-display/reftest.list
+++ b/layout/reftests/css-display/reftest.list
@@ -28,5 +28,4 @@ asserts(1) asserts-if(styloVsGecko,2) == display-contents-xbl-5.xul display-cont
== display-contents-writing-mode-1.html display-contents-writing-mode-1-ref.html
== display-contents-writing-mode-2.html display-contents-writing-mode-2-ref.html
needs-focus == display-contents-state-change.html display-contents-state-change-ref.html
-pref(layout.css.display-flow-root.enabled,true) == display-flow-root-001.html display-flow-root-001-ref.html
-pref(layout.css.display-flow-root.enabled,false) fails-if(styloVsGecko||stylo) == display-flow-root-001.html display-flow-root-disabled-001-ref.html
+== display-flow-root-001.html display-flow-root-001-ref.html
\ No newline at end of file
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index 2079b118a16323b3db9e79a59d3eab1629bc2dd2..b92a148339312ac3c71344156e0adf8d343c2350 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -1294,7 +1294,6 @@ KTableEntry nsCSSProps::kDisplayKTable[] = {
{ eCSSKeyword__webkit_flex, StyleDisplay::Flex },
{ eCSSKeyword__webkit_inline_flex, StyleDisplay::InlineFlex },
{ eCSSKeyword_contents, StyleDisplay::Contents },
- // The next entry is controlled by the layout.css.display-flow-root.enabled pref.
{ eCSSKeyword_flow_root, StyleDisplay::FlowRoot },
{ eCSSKeyword_UNKNOWN, -1 }
};
diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index 8559616344b735462fe369da34b3efca0a678c4d..6632e9a8139b032edf42e58f955a6e50b96e470b 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -7852,9 +7852,7 @@ if (IsCSSPropertyPrefEnabled("layout.css.float-logical-values.enabled")) {
gCSSProperties["clear"].invalid_values.push("inline-end");
}
-if (IsCSSPropertyPrefEnabled("layout.css.display-flow-root.enabled")) {
- gCSSProperties["display"].other_values.push("flow-root");
-}
+gCSSProperties["display"].other_values.push("flow-root");
// Copy aliased properties' fields from their alias targets.
for (var prop in gCSSProperties) {
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 6ae152a1bcbebb8d609a625eeaaa6180a8eb5c19..27c2617cad320c44f6bfad8702bf9737daff70f3 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2886,9 +2886,6 @@ pref("layout.css.grid-template-subgrid-value.enabled", false);
// Is support for CSS contain enabled?
pref("layout.css.contain.enabled", false);
-// Is support for CSS display:flow-root enabled?
-pref("layout.css.display-flow-root.enabled", true);
-
// Is support for CSS box-decoration-break enabled?
pref("layout.css.box-decoration-break.enabled", true);