Add m-esr52 at 52.6.0

1 files changed, 895 insertions, 0 deletions

diff --git a/layout/style/nsCSSProps.h b/layout/style/nsCSSProps.h
new file mode 100644
index 000000000..ab78e6174
--- /dev/null
+++ b/layout/style/nsCSSProps.h
@@ -0,0 +1,895 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * methods for dealing with CSS properties and tables of the keyword
+ * values they accept
+ */
+
+#ifndef nsCSSProps_h___
+#define nsCSSProps_h___
+
+#include <limits>
+#include <type_traits>
+#include "nsIAtom.h"
+#include "nsString.h"
+#include "nsCSSPropertyID.h"
+#include "nsStyleStructFwd.h"
+#include "nsCSSKeywords.h"
+#include "mozilla/CSSEnabledState.h"
+#include "mozilla/UseCounter.h"
+#include "mozilla/EnumTypeTraits.h"
+
+// Length of the "--" prefix on custom names (such as custom property names,
+// and, in the future, custom media query names).
+#define CSS_CUSTOM_NAME_PREFIX_LENGTH 2
+
+// Flags for ParseVariant method
+#define VARIANT_KEYWORD         0x000001  // K
+#define VARIANT_LENGTH          0x000002  // L
+#define VARIANT_PERCENT         0x000004  // P
+#define VARIANT_COLOR           0x000008  // C eCSSUnit_*Color, eCSSUnit_Ident (e.g.  "red")
+#define VARIANT_URL             0x000010  // U
+#define VARIANT_NUMBER          0x000020  // N
+#define VARIANT_INTEGER         0x000040  // I
+#define VARIANT_ANGLE           0x000080  // G
+#define VARIANT_FREQUENCY       0x000100  // F
+#define VARIANT_TIME            0x000200  // T
+#define VARIANT_STRING          0x000400  // S
+#define VARIANT_COUNTER         0x000800  //
+#define VARIANT_ATTR            0x001000  //
+#define VARIANT_IDENTIFIER      0x002000  // D
+#define VARIANT_IDENTIFIER_NO_INHERIT 0x004000 // like above, but excluding
+// 'inherit' and 'initial'
+#define VARIANT_AUTO            0x010000  // A
+#define VARIANT_INHERIT         0x020000  // H eCSSUnit_Initial, eCSSUnit_Inherit, eCSSUnit_Unset
+#define VARIANT_NONE            0x040000  // O
+#define VARIANT_NORMAL          0x080000  // M
+#define VARIANT_SYSFONT         0x100000  // eCSSUnit_System_Font
+#define VARIANT_GRADIENT        0x200000  // eCSSUnit_Gradient
+#define VARIANT_TIMING_FUNCTION 0x400000  // cubic-bezier() and steps()
+#define VARIANT_ALL             0x800000  //
+#define VARIANT_IMAGE_RECT    0x01000000  // eCSSUnit_Function
+// This is an extra bit that says that a VARIANT_ANGLE allows unitless zero:
+#define VARIANT_ZERO_ANGLE    0x02000000  // unitless zero for angles
+#define VARIANT_CALC          0x04000000  // eCSSUnit_Calc
+#define VARIANT_ELEMENT       0x08000000  // eCSSUnit_Element
+#define VARIANT_NONNEGATIVE_DIMENSION 0x10000000 // Only lengths greater than or equal to 0.0
+// Keyword used iff gfx.font_rendering.opentype_svg.enabled is true:
+#define VARIANT_OPENTYPE_SVG_KEYWORD 0x20000000
+#define VARIANT_ABSOLUTE_DIMENSION 0x40000000 // B Only lengths with absolute length unit
+
+// Variants that can consume more than one token
+#define VARIANT_MULTIPLE_TOKENS \
+  (VARIANT_COLOR |            /* rgb(...), hsl(...), etc. */                  \
+   VARIANT_COUNTER |          /* counter(...), counters(...) */               \
+   VARIANT_ATTR |             /* attr(...) */                                 \
+   VARIANT_GRADIENT |         /* linear-gradient(...), etc. */                \
+   VARIANT_TIMING_FUNCTION |  /* cubic-bezier(...), steps(...) */             \
+   VARIANT_IMAGE_RECT |       /* -moz-image-rect(...) */                      \
+   VARIANT_CALC |             /* calc(...) */                                 \
+   VARIANT_ELEMENT)           /* -moz-element(...) */
+
+// Common combinations of variants
+#define VARIANT_AL   (VARIANT_AUTO | VARIANT_LENGTH)
+#define VARIANT_LP   (VARIANT_LENGTH | VARIANT_PERCENT)
+#define VARIANT_LN   (VARIANT_LENGTH | VARIANT_NUMBER)
+#define VARIANT_AH   (VARIANT_AUTO | VARIANT_INHERIT)
+#define VARIANT_AHLP (VARIANT_AH | VARIANT_LP)
+#define VARIANT_AHI  (VARIANT_AH | VARIANT_INTEGER)
+#define VARIANT_AHK  (VARIANT_AH | VARIANT_KEYWORD)
+#define VARIANT_AHKLP (VARIANT_AHLP | VARIANT_KEYWORD)
+#define VARIANT_AHL  (VARIANT_AH | VARIANT_LENGTH)
+#define VARIANT_AHKL (VARIANT_AHK | VARIANT_LENGTH)
+#define VARIANT_HK   (VARIANT_INHERIT | VARIANT_KEYWORD)
+#define VARIANT_HKF  (VARIANT_HK | VARIANT_FREQUENCY)
+#define VARIANT_HKI  (VARIANT_HK | VARIANT_INTEGER)
+#define VARIANT_HKL  (VARIANT_HK | VARIANT_LENGTH)
+#define VARIANT_HKLP (VARIANT_HK | VARIANT_LP)
+#define VARIANT_HKLPO (VARIANT_HKLP | VARIANT_NONE)
+#define VARIANT_HL   (VARIANT_INHERIT | VARIANT_LENGTH)
+#define VARIANT_HI   (VARIANT_INHERIT | VARIANT_INTEGER)
+#define VARIANT_HLP  (VARIANT_HL | VARIANT_PERCENT)
+#define VARIANT_HLPN (VARIANT_HLP | VARIANT_NUMBER)
+#define VARIANT_HLPO (VARIANT_HLP | VARIANT_NONE)
+#define VARIANT_HTP  (VARIANT_INHERIT | VARIANT_TIME | VARIANT_PERCENT)
+#define VARIANT_HMK  (VARIANT_HK | VARIANT_NORMAL)
+#define VARIANT_HC   (VARIANT_INHERIT | VARIANT_COLOR)
+#define VARIANT_HCK  (VARIANT_HK | VARIANT_COLOR)
+#define VARIANT_HUK  (VARIANT_HK | VARIANT_URL)
+#define VARIANT_HUO  (VARIANT_INHERIT | VARIANT_URL | VARIANT_NONE)
+#define VARIANT_AHUO (VARIANT_AUTO | VARIANT_HUO)
+#define VARIANT_HPN  (VARIANT_INHERIT | VARIANT_PERCENT | VARIANT_NUMBER)
+#define VARIANT_PN   (VARIANT_PERCENT | VARIANT_NUMBER)
+#define VARIANT_ALPN (VARIANT_AL | VARIANT_PN)
+#define VARIANT_HN   (VARIANT_INHERIT | VARIANT_NUMBER)
+#define VARIANT_HON  (VARIANT_HN | VARIANT_NONE)
+#define VARIANT_HOS  (VARIANT_INHERIT | VARIANT_NONE | VARIANT_STRING)
+#define VARIANT_LPN  (VARIANT_LP | VARIANT_NUMBER)
+#define VARIANT_UK   (VARIANT_URL | VARIANT_KEYWORD)
+#define VARIANT_UO   (VARIANT_URL | VARIANT_NONE)
+#define VARIANT_ANGLE_OR_ZERO (VARIANT_ANGLE | VARIANT_ZERO_ANGLE)
+#define VARIANT_LB   (VARIANT_LENGTH | VARIANT_ABSOLUTE_DIMENSION)
+#define VARIANT_LBCALC (VARIANT_LB | VARIANT_CALC)
+#define VARIANT_LCALC  (VARIANT_LENGTH | VARIANT_CALC)
+#define VARIANT_LPCALC (VARIANT_LCALC | VARIANT_PERCENT)
+#define VARIANT_LNCALC (VARIANT_LCALC | VARIANT_NUMBER)
+#define VARIANT_LPNCALC (VARIANT_LNCALC | VARIANT_PERCENT)
+#define VARIANT_IMAGE   (VARIANT_URL | VARIANT_NONE | VARIANT_GRADIENT | \
+                        VARIANT_IMAGE_RECT | VARIANT_ELEMENT)
+
+// Flags for the kFlagsTable bitfield (flags_ in nsCSSPropList.h)
+
+// This property is a logical property (such as padding-inline-start).
+#define CSS_PROPERTY_LOGICAL                      (1<<0)
+
+#define CSS_PROPERTY_VALUE_LIST_USES_COMMAS       (1<<1) /* otherwise spaces */
+
+#define CSS_PROPERTY_APPLIES_TO_FIRST_LETTER      (1<<2)
+#define CSS_PROPERTY_APPLIES_TO_FIRST_LINE        (1<<3)
+#define CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE \
+  (CSS_PROPERTY_APPLIES_TO_FIRST_LETTER | CSS_PROPERTY_APPLIES_TO_FIRST_LINE)
+
+// Note that 'background-color' is ignored differently from the other
+// properties that have this set, but that's just special-cased.
+#define CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED (1<<4)
+
+// A property that needs to have image loads started when a URL value
+// for the property is used for an element.  This is supported only
+// for a few possible value formats: image directly in the value; list
+// of images; and with CSS_PROPERTY_IMAGE_IS_IN_ARRAY_0, image in slot
+// 0 of an array, or list of such arrays.
+#define CSS_PROPERTY_START_IMAGE_LOADS            (1<<5)
+
+// Should be set only for properties with START_IMAGE_LOADS.  Indicates
+// that the property has an array value with a URL/image value at index
+// 0 in the array, rather than the URL/image being in the value or value
+// list.
+#define CSS_PROPERTY_IMAGE_IS_IN_ARRAY_0          (1<<6)
+
+// This is a logical property that represents some value associated with
+// a logical axis rather than a logical box side, and thus has two
+// corresponding physical properties it could set rather than four.  For
+// example, the block-size logical property has this flag set, as it
+// represents the size in either the block or inline axis dimensions, and
+// has two corresponding physical properties, width and height.  Must not
+// be used in conjunction with CSS_PROPERTY_LOGICAL_END_EDGE.
+#define CSS_PROPERTY_LOGICAL_AXIS                 (1<<7)
+
+// This property allows calc() between lengths and percentages and
+// stores such calc() expressions in its style structs (typically in an
+// nsStyleCoord, although this is not the case for 'background-position'
+// and 'background-size').
+#define CSS_PROPERTY_STORES_CALC                  (1<<8)
+
+// Define what mechanism the CSS parser uses for parsing the property.
+// See CSSParserImpl::ParseProperty(nsCSSPropertyID).  Don't use 0 so that
+// we can verify that every property sets one of the values.
+//
+// CSS_PROPERTY_PARSE_FUNCTION must be used for shorthand properties,
+// since it's the only mechanism that allows appending values for
+// separate properties.  Longhand properties that require custom parsing
+// functions should prefer using CSS_PROPERTY_PARSE_VALUE (or
+// CSS_PROPERTY_PARSE_VALUE_LIST) and
+// CSS_PROPERTY_VALUE_PARSER_FUNCTION, though a number of existing
+// longhand properties use CSS_PROPERTY_PARSE_FUNCTION instead.
+#define CSS_PROPERTY_PARSE_PROPERTY_MASK          (7<<9)
+#define CSS_PROPERTY_PARSE_INACCESSIBLE           (1<<9)
+#define CSS_PROPERTY_PARSE_FUNCTION               (2<<9)
+#define CSS_PROPERTY_PARSE_VALUE                  (3<<9)
+#define CSS_PROPERTY_PARSE_VALUE_LIST             (4<<9)
+
+// See CSSParserImpl::ParseSingleValueProperty and comment above
+// CSS_PROPERTY_PARSE_FUNCTION (which is different).
+#define CSS_PROPERTY_VALUE_PARSER_FUNCTION        (1<<12)
+static_assert((CSS_PROPERTY_PARSE_PROPERTY_MASK &
+               CSS_PROPERTY_VALUE_PARSER_FUNCTION) == 0,
+              "didn't leave enough room for the parse property constants");
+
+#define CSS_PROPERTY_VALUE_RESTRICTION_MASK       (3<<13)
+// The parser (in particular, CSSParserImpl::ParseSingleValueProperty)
+// should enforce that the value of this property must be 0 or larger.
+#define CSS_PROPERTY_VALUE_NONNEGATIVE            (1<<13)
+// The parser (in particular, CSSParserImpl::ParseSingleValueProperty)
+// should enforce that the value of this property must be 1 or larger.
+#define CSS_PROPERTY_VALUE_AT_LEAST_ONE           (2<<13)
+
+// Does this property support the hashless hex color quirk in quirks mode?
+#define CSS_PROPERTY_HASHLESS_COLOR_QUIRK         (1<<15)
+
+// Does this property support the unitless length quirk in quirks mode?
+#define CSS_PROPERTY_UNITLESS_LENGTH_QUIRK        (1<<16)
+
+// Is this property (which must be a shorthand) really an alias?
+#define CSS_PROPERTY_IS_ALIAS                     (1<<17)
+
+// Does the property apply to ::placeholder?
+#define CSS_PROPERTY_APPLIES_TO_PLACEHOLDER       (1<<18)
+
+// This property is allowed in an @page rule.
+#define CSS_PROPERTY_APPLIES_TO_PAGE_RULE         (1<<19)
+
+// This property's getComputedStyle implementation requires layout to be
+// flushed.
+#define CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH     (1<<20)
+
+// This property requires a stacking context.
+#define CSS_PROPERTY_CREATES_STACKING_CONTEXT     (1<<21)
+
+// The following two flags along with the pref defines where the this
+// property can be used:
+// * If none of the two flags is presented, the pref completely controls
+//   the availability of this property. And in that case, if it has no
+//   pref, this property is usable everywhere.
+// * If any of the flags is set, this property is always enabled in the
+//   specific contexts regardless of the value of the pref. If there is
+//   no pref for this property at all in this case, it is an internal-
+//   only property, which cannot be used anywhere else, and should be
+//   wrapped in "#ifndef CSS_PROP_LIST_EXCLUDE_INTERNAL".
+// Note that, these flags have no effect on the use of aliases of this
+// property.
+// Furthermore, for the purposes of animation (including triggering
+// transitions) these flags are ignored. That is, if the property is disabled
+// by a pref, we will *not* run animations or transitions on it even in
+// UA sheets or chrome.
+#define CSS_PROPERTY_ENABLED_MASK                 (3<<22)
+#define CSS_PROPERTY_ENABLED_IN_UA_SHEETS         (1<<22)
+#define CSS_PROPERTY_ENABLED_IN_CHROME            (1<<23)
+#define CSS_PROPERTY_ENABLED_IN_UA_SHEETS_AND_CHROME \
+  (CSS_PROPERTY_ENABLED_IN_UA_SHEETS | CSS_PROPERTY_ENABLED_IN_CHROME)
+
+// This property's unitless values are pixels.
+#define CSS_PROPERTY_NUMBERS_ARE_PIXELS           (1<<24)
+
+// This property is a logical property for one of the two block axis
+// sides (such as margin-block-start or margin-block-end).  Must only be
+// set if CSS_PROPERTY_LOGICAL is set.  When not set, the logical
+// property is for one of the two inline axis sides (such as
+// margin-inline-start or margin-inline-end).
+#define CSS_PROPERTY_LOGICAL_BLOCK_AXIS           (1<<25)
+
+// This property is a logical property for the "end" edge of the
+// axis determined by the presence or absence of
+// CSS_PROPERTY_LOGICAL_BLOCK_AXIS (such as margin-block-end or
+// margin-inline-end).  Must only be set if CSS_PROPERTY_LOGICAL is set.
+// When not set, the logical property is for the "start" edge (such as
+// margin-block-start or margin-inline-start).
+#define CSS_PROPERTY_LOGICAL_END_EDGE             (1<<26)
+
+// This property can be animated on the compositor.
+#define CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR    (1<<27)
+
+// This property is an internal property that is not represented
+// in the DOM.  Properties with this flag must be defined in an #ifndef
+// CSS_PROP_LIST_EXCLUDE_INTERNAL section of nsCSSPropList.h.
+#define CSS_PROPERTY_INTERNAL                     (1<<28)
+
+// This property has values that can establish a containing block for
+// fixed positioned and absolutely positioned elements.
+// This should be set for any properties that can cause an element to be
+// such a containing block, as implemented in
+// nsStyleDisplay::IsFixedPosContainingBlock.
+#define CSS_PROPERTY_FIXPOS_CB                    (1<<29)
+
+// This property has values that can establish a containing block for
+// absolutely positioned elements.
+// This should be set for any properties that can cause an element to be
+// such a containing block, as implemented in
+// nsStyleDisplay::IsAbsPosContainingBlock.
+// It does not need to be set for properties that also have
+// CSS_PROPERTY_FIXPOS_CB set.
+#define CSS_PROPERTY_ABSPOS_CB                    (1<<30)
+
+/**
+ * Types of animatable values.
+ */
+enum nsStyleAnimType {
+  // requires a custom implementation in
+  // StyleAnimationValue::ExtractComputedValue
+  eStyleAnimType_Custom,
+
+  // nsStyleCoord with animatable values
+  eStyleAnimType_Coord,
+
+  // same as Coord, except for one side of an nsStyleSides
+  // listed in the same order as the NS_STYLE_* constants
+  eStyleAnimType_Sides_Top,
+  eStyleAnimType_Sides_Right,
+  eStyleAnimType_Sides_Bottom,
+  eStyleAnimType_Sides_Left,
+
+  // similar, but for the *pair* of coord members of an nsStyleCorners
+  // for the relevant corner
+  eStyleAnimType_Corner_TopLeft,
+  eStyleAnimType_Corner_TopRight,
+  eStyleAnimType_Corner_BottomRight,
+  eStyleAnimType_Corner_BottomLeft,
+
+  // nscoord values
+  eStyleAnimType_nscoord,
+
+  // float values
+  eStyleAnimType_float,
+
+  // nscolor values
+  eStyleAnimType_Color,
+
+  // StyleComplexColor values
+  eStyleAnimType_ComplexColor,
+
+  // nsStyleSVGPaint values
+  eStyleAnimType_PaintServer,
+
+  // RefPtr<nsCSSShadowArray> values
+  eStyleAnimType_Shadow,
+
+  // discrete values
+  eStyleAnimType_Discrete,
+
+  // property not animatable
+  eStyleAnimType_None
+};
+
+// Empty class derived from nsIAtom so that function signatures can
+// require an atom from the atom list.
+class nsICSSProperty : public nsIAtom {};
+
+class nsCSSProps {
+public:
+  typedef mozilla::CSSEnabledState EnabledState;
+
+  struct KTableEntry
+  {
+    // KTableEntry objects can be initialized either with an int16_t value
+    // or a value of an enumeration type that can fit within an int16_t.
+
+    constexpr KTableEntry(nsCSSKeyword aKeyword, int16_t aValue)
+      : mKeyword(aKeyword)
+      , mValue(aValue)
+    {
+    }
+
+    template<typename T,
+             typename = typename std::enable_if<std::is_enum<T>::value>::type>
+    constexpr KTableEntry(nsCSSKeyword aKeyword, T aValue)
+      : mKeyword(aKeyword)
+      , mValue(static_cast<int16_t>(aValue))
+    {
+      static_assert(mozilla::EnumTypeFitsWithin<T, int16_t>::value,
+                    "aValue must be an enum that fits within mValue");
+    }
+
+    nsCSSKeyword mKeyword;
+    int16_t mValue;
+  };
+
+  static void AddRefTable(void);
+  static void ReleaseTable(void);
+
+  // Looks up the property with name aProperty and returns its corresponding
+  // nsCSSPropertyID value.  If aProperty is the name of a custom property,
+  // then eCSSPropertyExtra_variable will be returned.
+  static nsCSSPropertyID LookupProperty(const nsAString& aProperty,
+                                      EnabledState aEnabled);
+  static nsCSSPropertyID LookupProperty(const nsACString& aProperty,
+                                      EnabledState aEnabled);
+  // As above, but looked up using a property's IDL name.
+  // eCSSPropertyExtra_variable won't be returned from these methods.
+  static nsCSSPropertyID LookupPropertyByIDLName(
+      const nsAString& aPropertyIDLName,
+      EnabledState aEnabled);
+  static nsCSSPropertyID LookupPropertyByIDLName(
+      const nsACString& aPropertyIDLName,
+      EnabledState aEnabled);
+
+  // Returns whether aProperty is a custom property name, i.e. begins with
+  // "--".  This assumes that the CSS Variables pref has been enabled.
+  static bool IsCustomPropertyName(const nsAString& aProperty);
+  static bool IsCustomPropertyName(const nsACString& aProperty);
+
+  static inline bool IsShorthand(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return (aProperty >= eCSSProperty_COUNT_no_shorthands);
+  }
+
+  // Must be given a longhand property.
+  static bool IsInherited(nsCSSPropertyID aProperty);
+
+  // Same but for @font-face descriptors
+  static nsCSSFontDesc LookupFontDesc(const nsAString& aProperty);
+  static nsCSSFontDesc LookupFontDesc(const nsACString& aProperty);
+
+  // For @counter-style descriptors
+  static nsCSSCounterDesc LookupCounterDesc(const nsAString& aProperty);
+  static nsCSSCounterDesc LookupCounterDesc(const nsACString& aProperty);
+
+  // For predefined counter styles which need to be lower-cased during parse
+  static bool IsPredefinedCounterStyle(const nsAString& aStyle);
+  static bool IsPredefinedCounterStyle(const nsACString& aStyle);
+
+  // Given a property enum, get the string value
+  static const nsAFlatCString& GetStringValue(nsCSSPropertyID aProperty);
+  static const nsAFlatCString& GetStringValue(nsCSSFontDesc aFontDesc);
+  static const nsAFlatCString& GetStringValue(nsCSSCounterDesc aCounterDesc);
+
+  // Given a CSS Property and a Property Enum Value
+  // Return back a const nsString& representation of the
+  // value. Return back nullstr if no value is found
+  static const nsAFlatCString& LookupPropertyValue(nsCSSPropertyID aProperty, int32_t aValue);
+
+  // Get a color name for a predefined color value like buttonhighlight or activeborder
+  // Sets the aStr param to the name of the propertyID
+  static bool GetColorName(int32_t aPropID, nsCString &aStr);
+
+  // Returns the index of |aKeyword| in |aTable|, if it exists there;
+  // otherwise, returns -1.
+  // NOTE: Generally, clients should call FindKeyword() instead of this method.
+  static int32_t FindIndexOfKeyword(nsCSSKeyword aKeyword,
+                                    const KTableEntry aTable[]);
+
+  // Find |aKeyword| in |aTable|, if found set |aValue| to its corresponding value.
+  // If not found, return false and do not set |aValue|.
+  static bool FindKeyword(nsCSSKeyword aKeyword, const KTableEntry aTable[],
+                          int32_t& aValue);
+  // Return the first keyword in |aTable| that has the corresponding value |aValue|.
+  // Return |eCSSKeyword_UNKNOWN| if not found.
+  static nsCSSKeyword ValueToKeywordEnum(int32_t aValue,
+                                         const KTableEntry aTable[]);
+  template<typename T,
+           typename = typename std::enable_if<std::is_enum<T>::value>::type>
+  static nsCSSKeyword ValueToKeywordEnum(T aValue,
+                                         const KTableEntry aTable[])
+  {
+    static_assert(mozilla::EnumTypeFitsWithin<T, int16_t>::value,
+                  "aValue must be an enum that fits within KTableEntry::mValue");
+    return ValueToKeywordEnum(static_cast<int16_t>(aValue), aTable);
+  }
+  // Ditto but as a string, return "" when not found.
+  static const nsAFlatCString& ValueToKeyword(int32_t aValue,
+                                              const KTableEntry aTable[]);
+  template<typename T,
+           typename = typename std::enable_if<std::is_enum<T>::value>::type>
+  static const nsAFlatCString& ValueToKeyword(T aValue,
+                                              const KTableEntry aTable[])
+  {
+    static_assert(mozilla::EnumTypeFitsWithin<T, int16_t>::value,
+                  "aValue must be an enum that fits within KTableEntry::mValue");
+    return ValueToKeyword(static_cast<int16_t>(aValue), aTable);
+  }
+
+  static const nsStyleStructID kSIDTable[eCSSProperty_COUNT_no_shorthands];
+  static const KTableEntry* const kKeywordTableTable[eCSSProperty_COUNT_no_shorthands];
+  static const nsStyleAnimType kAnimTypeTable[eCSSProperty_COUNT_no_shorthands];
+  static const ptrdiff_t
+    kStyleStructOffsetTable[eCSSProperty_COUNT_no_shorthands];
+
+private:
+  static const uint32_t        kFlagsTable[eCSSProperty_COUNT];
+
+public:
+  static inline bool PropHasFlags(nsCSSPropertyID aProperty, uint32_t aFlags)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    MOZ_ASSERT(!(aFlags & CSS_PROPERTY_PARSE_PROPERTY_MASK),
+               "The CSS_PROPERTY_PARSE_* values are not bitflags; don't pass "
+               "them to PropHasFlags.  You probably want PropertyParseType "
+               "instead.");
+    return (nsCSSProps::kFlagsTable[aProperty] & aFlags) == aFlags;
+  }
+
+  static inline uint32_t PropertyParseType(nsCSSPropertyID aProperty)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return nsCSSProps::kFlagsTable[aProperty] &
+           CSS_PROPERTY_PARSE_PROPERTY_MASK;
+  }
+
+  static inline uint32_t ValueRestrictions(nsCSSPropertyID aProperty)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return nsCSSProps::kFlagsTable[aProperty] &
+           CSS_PROPERTY_VALUE_RESTRICTION_MASK;
+  }
+
+private:
+  // Lives in nsCSSParser.cpp for the macros it depends on.
+  static const uint32_t kParserVariantTable[eCSSProperty_COUNT_no_shorthands];
+
+public:
+  static inline uint32_t ParserVariant(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT_no_shorthands,
+               "out of range");
+    return nsCSSProps::kParserVariantTable[aProperty];
+  }
+
+private:
+  // A table for shorthand properties.  The appropriate index is the
+  // property ID minus eCSSProperty_COUNT_no_shorthands.
+  static const nsCSSPropertyID *const
+    kSubpropertyTable[eCSSProperty_COUNT - eCSSProperty_COUNT_no_shorthands];
+
+public:
+  static inline
+  const nsCSSPropertyID * SubpropertyEntryFor(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(eCSSProperty_COUNT_no_shorthands <= aProperty &&
+               aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return nsCSSProps::kSubpropertyTable[aProperty -
+                                         eCSSProperty_COUNT_no_shorthands];
+  }
+
+  // Returns an eCSSProperty_UNKNOWN-terminated array of the shorthand
+  // properties containing |aProperty|, sorted from those that contain
+  // the most properties to those that contain the least.
+  static const nsCSSPropertyID * ShorthandsContaining(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(gShorthandsContainingPool, "uninitialized");
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT_no_shorthands,
+               "out of range");
+    return gShorthandsContainingTable[aProperty];
+  }
+private:
+  // gShorthandsContainingTable is an array of the return values for
+  // ShorthandsContaining (arrays of nsCSSPropertyID terminated by
+  // eCSSProperty_UNKNOWN) pointing into memory in
+  // gShorthandsContainingPool (which contains all of those arrays in a
+  // single allocation, and is the one pointer that should be |free|d).
+  static nsCSSPropertyID *gShorthandsContainingTable[eCSSProperty_COUNT_no_shorthands];
+  static nsCSSPropertyID* gShorthandsContainingPool;
+  static bool BuildShorthandsContainingTable();
+
+private:
+  static const size_t gPropertyCountInStruct[nsStyleStructID_Length];
+  static const size_t gPropertyIndexInStruct[eCSSProperty_COUNT_no_shorthands];
+public:
+  /**
+   * Return the number of properties that must be cascaded when
+   * nsRuleNode builds the nsStyle* for aSID.
+   */
+  static size_t PropertyCountInStruct(nsStyleStructID aSID) {
+    MOZ_ASSERT(0 <= aSID && aSID < nsStyleStructID_Length,
+               "out of range");
+    return gPropertyCountInStruct[aSID];
+  }
+  /**
+   * Return an index for aProperty that is unique within its SID and in
+   * the range 0 <= index < PropertyCountInStruct(aSID).
+   */
+  static size_t PropertyIndexInStruct(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT_no_shorthands,
+               "out of range");
+    return gPropertyIndexInStruct[aProperty];
+  }
+
+private:
+  // A table for logical property groups.  Indexes are
+  // nsCSSPropertyLogicalGroup values.
+  static const nsCSSPropertyID* const
+    kLogicalGroupTable[eCSSPropertyLogicalGroup_COUNT];
+
+public:
+  /**
+   * Returns an array of longhand physical properties which can be set by
+   * the argument, which must be a logical longhand property.  The returned
+   * array is terminated by an eCSSProperty_UNKNOWN value.  For example,
+   * given eCSSProperty_margin_block_start, returns an array of the four
+   * properties eCSSProperty_margin_top, eCSSProperty_margin_right,
+   * eCSSProperty_margin_bottom and eCSSProperty_margin_left, followed
+   * by the sentinel.
+   *
+   * When called with a property that has the CSS_PROPERTY_LOGICAL_AXIS
+   * flag, the returned array will have two values preceding the sentinel;
+   * otherwise it will have four.
+   *
+   * (Note that the running time of this function is proportional to the
+   * number of logical longhand properties that exist.  If we start
+   * getting too many of these properties, we should make kLogicalGroupTable
+   * be a simple array of eCSSProperty_COUNT length.)
+   */
+  static const nsCSSPropertyID* LogicalGroup(nsCSSPropertyID aProperty);
+
+private:
+  static bool gPropertyEnabled[eCSSProperty_COUNT_with_aliases];
+
+private:
+  // Defined in the generated nsCSSPropsGenerated.inc.
+  static const char* const kIDLNameTable[eCSSProperty_COUNT];
+
+public:
+  /**
+   * Returns the IDL name of the specified property, which must be a
+   * longhand, logical or shorthand property.  The IDL name is the property
+   * name with any hyphen-lowercase character pairs replaced by an
+   * uppercase character:
+   * https://drafts.csswg.org/cssom/#css-property-to-idl-attribute
+   *
+   * As a special case, the string "cssFloat" is returned for the float
+   * property.  nullptr is returned for internal properties.
+   */
+  static const char* PropertyIDLName(nsCSSPropertyID aProperty)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return kIDLNameTable[aProperty];
+  }
+
+private:
+  static const int32_t kIDLNameSortPositionTable[eCSSProperty_COUNT];
+
+public:
+  /**
+   * Returns the position of the specified property in a list of all
+   * properties sorted by their IDL name.
+   */
+  static int32_t PropertyIDLNameSortPosition(nsCSSPropertyID aProperty)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT,
+               "out of range");
+    return kIDLNameSortPositionTable[aProperty];
+  }
+
+  static bool IsEnabled(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT_with_aliases,
+               "out of range");
+    return gPropertyEnabled[aProperty];
+  }
+
+  // A table for the use counter associated with each CSS property.  If a
+  // property does not have a use counter defined in UseCounters.conf, then
+  // its associated entry is |eUseCounter_UNKNOWN|.
+  static const mozilla::UseCounter gPropertyUseCounter[eCSSProperty_COUNT_no_shorthands];
+
+public:
+
+  static mozilla::UseCounter UseCounterFor(nsCSSPropertyID aProperty) {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT_no_shorthands,
+               "out of range");
+    return gPropertyUseCounter[aProperty];
+  }
+
+  static bool IsEnabled(nsCSSPropertyID aProperty, EnabledState aEnabled)
+  {
+    if (IsEnabled(aProperty)) {
+      return true;
+    }
+    if (aEnabled == EnabledState::eIgnoreEnabledState) {
+      return true;
+    }
+    if ((aEnabled & EnabledState::eInUASheets) &&
+        PropHasFlags(aProperty, CSS_PROPERTY_ENABLED_IN_UA_SHEETS))
+    {
+      return true;
+    }
+    if ((aEnabled & EnabledState::eInChrome) &&
+        PropHasFlags(aProperty, CSS_PROPERTY_ENABLED_IN_CHROME))
+    {
+      return true;
+    }
+    return false;
+  }
+
+public:
+  static void AddRefAtoms();
+  static nsICSSProperty* AtomForProperty(nsCSSPropertyID aProperty)
+  {
+    MOZ_ASSERT(0 <= aProperty && aProperty < eCSSProperty_COUNT);
+    return gPropertyAtomTable[aProperty];
+  }
+
+#define CSS_PROP(name_, id_, ...) static nsICSSProperty* id_;
+#define CSS_PROP_SHORTHAND(name_, id_, ...) CSS_PROP(name_, id_, ...)
+#define CSS_PROP_LIST_INCLUDE_LOGICAL
+#include "nsCSSPropList.h"
+#undef CSS_PROP_LIST_INCLUDE_LOGICAL
+#undef CSS_PROP_SHORTHAND
+#undef CSS_PROP
+
+private:
+  static nsICSSProperty* gPropertyAtomTable[eCSSProperty_COUNT];
+
+public:
+
+// Storing the enabledstate_ value in an nsCSSPropertyID variable is a small hack
+// to avoid needing a separate variable declaration for its real type
+// (CSSEnabledState), which would then require using a block and
+// therefore a pair of macros by consumers for the start and end of the loop.
+#define CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(it_, prop_, enabledstate_)   \
+  for (const nsCSSPropertyID *it_ = nsCSSProps::SubpropertyEntryFor(prop_), \
+                            es_ = (nsCSSPropertyID)((enabledstate_) |       \
+                                                  CSSEnabledState(0));    \
+       *it_ != eCSSProperty_UNKNOWN; ++it_)                               \
+    if (nsCSSProps::IsEnabled(*it_, (mozilla::CSSEnabledState) es_))
+
+  // Keyword/Enum value tables
+  static const KTableEntry kAnimationDirectionKTable[];
+  static const KTableEntry kAnimationFillModeKTable[];
+  static const KTableEntry kAnimationIterationCountKTable[];
+  static const KTableEntry kAnimationPlayStateKTable[];
+  static const KTableEntry kAnimationTimingFunctionKTable[];
+  static const KTableEntry kAppearanceKTable[];
+  static const KTableEntry kAzimuthKTable[];
+  static const KTableEntry kBackfaceVisibilityKTable[];
+  static const KTableEntry kTransformStyleKTable[];
+  static const KTableEntry kImageLayerAttachmentKTable[];
+  static const KTableEntry kImageLayerOriginKTable[];
+  static const KTableEntry kImageLayerPositionKTable[];
+  static const KTableEntry kImageLayerRepeatKTable[];
+  static const KTableEntry kImageLayerRepeatPartKTable[];
+  static const KTableEntry kImageLayerSizeKTable[];
+  static const KTableEntry kImageLayerCompositeKTable[];
+  static const KTableEntry kImageLayerModeKTable[];
+  // Not const because we modify its entries when the pref
+  // "layout.css.background-clip.text" changes:
+  static KTableEntry kBackgroundClipKTable[];
+  static const KTableEntry kBlendModeKTable[];
+  static const KTableEntry kBorderCollapseKTable[];
+  static const KTableEntry kBorderImageRepeatKTable[];
+  static const KTableEntry kBorderImageSliceKTable[];
+  static const KTableEntry kBorderStyleKTable[];
+  static const KTableEntry kBorderWidthKTable[];
+  static const KTableEntry kBoxAlignKTable[];
+  static const KTableEntry kBoxDecorationBreakKTable[];
+  static const KTableEntry kBoxDirectionKTable[];
+  static const KTableEntry kBoxOrientKTable[];
+  static const KTableEntry kBoxPackKTable[];
+  static const KTableEntry kClipPathGeometryBoxKTable[];
+  static const KTableEntry kCounterRangeKTable[];
+  static const KTableEntry kCounterSpeakAsKTable[];
+  static const KTableEntry kCounterSymbolsSystemKTable[];
+  static const KTableEntry kCounterSystemKTable[];
+  static const KTableEntry kDominantBaselineKTable[];
+  static const KTableEntry kShapeRadiusKTable[];
+  static const KTableEntry kFillRuleKTable[];
+  static const KTableEntry kFilterFunctionKTable[];
+  static const KTableEntry kImageRenderingKTable[];
+  static const KTableEntry kShapeOutsideShapeBoxKTable[];
+  static const KTableEntry kShapeRenderingKTable[];
+  static const KTableEntry kStrokeLinecapKTable[];
+  static const KTableEntry kStrokeLinejoinKTable[];
+  static const KTableEntry kStrokeContextValueKTable[];
+  static const KTableEntry kVectorEffectKTable[];
+  static const KTableEntry kTextAnchorKTable[];
+  static const KTableEntry kTextRenderingKTable[];
+  static const KTableEntry kColorAdjustKTable[];
+  static const KTableEntry kColorInterpolationKTable[];
+  static const KTableEntry kColumnFillKTable[];
+  static const KTableEntry kBoxPropSourceKTable[];
+  static const KTableEntry kBoxShadowTypeKTable[];
+  static const KTableEntry kBoxSizingKTable[];
+  static const KTableEntry kCaptionSideKTable[];
+  // Not const because we modify its entries when the pref
+  // "layout.css.float-logical-values.enabled" changes:
+  static KTableEntry kClearKTable[];
+  static const KTableEntry kColorKTable[];
+  static const KTableEntry kContentKTable[];
+  static const KTableEntry kControlCharacterVisibilityKTable[];
+  static const KTableEntry kCursorKTable[];
+  static const KTableEntry kDirectionKTable[];
+  // Not const because we modify its entries when various 
+  // "layout.css.*.enabled" prefs changes:
+  static KTableEntry kDisplayKTable[];
+  static const KTableEntry kElevationKTable[];
+  static const KTableEntry kEmptyCellsKTable[];
+  // -- tables for parsing the {align,justify}-{content,items,self} properties --
+  static const KTableEntry kAlignAllKeywords[];
+  static const KTableEntry kAlignOverflowPosition[]; // <overflow-position>
+  static const KTableEntry kAlignSelfPosition[];     // <self-position>
+  static const KTableEntry kAlignLegacy[];           // 'legacy'
+  static const KTableEntry kAlignLegacyPosition[];   // 'left/right/center'
+  static const KTableEntry kAlignAutoNormalStretchBaseline[]; // 'auto/normal/stretch/baseline'
+  static const KTableEntry kAlignNormalStretchBaseline[]; // 'normal/stretch/baseline'
+  static const KTableEntry kAlignNormalBaseline[]; // 'normal/baseline'
+  static const KTableEntry kAlignContentDistribution[]; // <content-distribution>
+  static const KTableEntry kAlignContentPosition[]; // <content-position>
+  // -- tables for auto-completion of the {align,justify}-{content,items,self} properties --
+  static const KTableEntry kAutoCompletionAlignJustifySelf[];
+  static const KTableEntry kAutoCompletionAlignItems[];
+  static const KTableEntry kAutoCompletionAlignJustifyContent[];
+  // ------------------------------------------------------------------
+  static const KTableEntry kFlexDirectionKTable[];
+  static const KTableEntry kFlexWrapKTable[];
+  // Not const because we modify its entries when the pref
+  // "layout.css.float-logical-values.enabled" changes:
+  static KTableEntry kFloatKTable[];
+  static const KTableEntry kFloatEdgeKTable[];
+  static const KTableEntry kFontDisplayKTable[];
+  static const KTableEntry kFontKTable[];
+  static const KTableEntry kFontKerningKTable[];
+  static const KTableEntry kFontSizeKTable[];
+  static const KTableEntry kFontSmoothingKTable[];
+  static const KTableEntry kFontStretchKTable[];
+  static const KTableEntry kFontStyleKTable[];
+  static const KTableEntry kFontSynthesisKTable[];
+  static const KTableEntry kFontVariantKTable[];
+  static const KTableEntry kFontVariantAlternatesKTable[];
+  static const KTableEntry kFontVariantAlternatesFuncsKTable[];
+  static const KTableEntry kFontVariantCapsKTable[];
+  static const KTableEntry kFontVariantEastAsianKTable[];
+  static const KTableEntry kFontVariantLigaturesKTable[];
+  static const KTableEntry kFontVariantNumericKTable[];
+  static const KTableEntry kFontVariantPositionKTable[];
+  static const KTableEntry kFontWeightKTable[];
+  static const KTableEntry kGridAutoFlowKTable[];
+  static const KTableEntry kGridTrackBreadthKTable[];
+  static const KTableEntry kHyphensKTable[];
+  static const KTableEntry kImageOrientationKTable[];
+  static const KTableEntry kImageOrientationFlipKTable[];
+  static const KTableEntry kIsolationKTable[];
+  static const KTableEntry kIMEModeKTable[];
+  static const KTableEntry kLineHeightKTable[];
+  static const KTableEntry kListStylePositionKTable[];
+  static const KTableEntry kListStyleKTable[];
+  static const KTableEntry kMaskTypeKTable[];
+  static const KTableEntry kMathVariantKTable[];
+  static const KTableEntry kMathDisplayKTable[];
+  static const KTableEntry kContainKTable[];
+  static const KTableEntry kContextOpacityKTable[];
+  static const KTableEntry kContextPatternKTable[];
+  static const KTableEntry kObjectFitKTable[];
+  static const KTableEntry kOrientKTable[];
+  static const KTableEntry kOutlineStyleKTable[];
+  static const KTableEntry kOverflowKTable[];
+  static const KTableEntry kOverflowSubKTable[];
+  static const KTableEntry kOverflowClipBoxKTable[];
+  static const KTableEntry kOverflowWrapKTable[];
+  static const KTableEntry kPageBreakKTable[];
+  static const KTableEntry kPageBreakInsideKTable[];
+  static const KTableEntry kPageMarksKTable[];
+  static const KTableEntry kPageSizeKTable[];
+  static const KTableEntry kPitchKTable[];
+  static const KTableEntry kPointerEventsKTable[];
+  static const KTableEntry kPositionKTable[];
+  static const KTableEntry kRadialGradientShapeKTable[];
+  static const KTableEntry kRadialGradientSizeKTable[];
+  static const KTableEntry kRadialGradientLegacySizeKTable[];
+  static const KTableEntry kResizeKTable[];
+  static const KTableEntry kRubyAlignKTable[];
+  static const KTableEntry kRubyPositionKTable[];
+  static const KTableEntry kScrollBehaviorKTable[];
+  static const KTableEntry kScrollSnapTypeKTable[];
+  static const KTableEntry kSpeakKTable[];
+  static const KTableEntry kSpeakHeaderKTable[];
+  static const KTableEntry kSpeakNumeralKTable[];
+  static const KTableEntry kSpeakPunctuationKTable[];
+  static const KTableEntry kSpeechRateKTable[];
+  static const KTableEntry kStackSizingKTable[];
+  static const KTableEntry kTableLayoutKTable[];
+  // Not const because we modify its entries when the pref
+  // "layout.css.text-align-unsafe-value.enabled" changes:
+  static KTableEntry kTextAlignKTable[];
+  static KTableEntry kTextAlignLastKTable[];
+  static const KTableEntry kTextCombineUprightKTable[];
+  static const KTableEntry kTextDecorationLineKTable[];
+  static const KTableEntry kTextDecorationStyleKTable[];
+  static const KTableEntry kTextEmphasisPositionKTable[];
+  static const KTableEntry kTextEmphasisStyleFillKTable[];
+  static const KTableEntry kTextEmphasisStyleShapeKTable[];
+  static const KTableEntry kTextOrientationKTable[];
+  static const KTableEntry kTextOverflowKTable[];
+  static const KTableEntry kTextTransformKTable[];
+  static const KTableEntry kTouchActionKTable[];
+  static const KTableEntry kTopLayerKTable[];
+  static const KTableEntry kTransformBoxKTable[];
+  static const KTableEntry kTransitionTimingFunctionKTable[];
+  static const KTableEntry kUnicodeBidiKTable[];
+  static const KTableEntry kUserFocusKTable[];
+  static const KTableEntry kUserInputKTable[];
+  static const KTableEntry kUserModifyKTable[];
+  static const KTableEntry kUserSelectKTable[];
+  static const KTableEntry kVerticalAlignKTable[];
+  static const KTableEntry kVisibilityKTable[];
+  static const KTableEntry kVolumeKTable[];
+  static const KTableEntry kWhitespaceKTable[];
+  static const KTableEntry kWidthKTable[]; // also min-width, max-width
+  static const KTableEntry kWindowDraggingKTable[];
+  static const KTableEntry kWindowShadowKTable[];
+  static const KTableEntry kWordBreakKTable[];
+  static const KTableEntry kWritingModeKTable[];
+};
+
+#endif /* nsCSSProps_h___ */