Bug 1607826 - Use <type_traits> more in layout. r=TYLin

Differential Revision: https://phabricator.services.mozilla.com/D59160

--HG--
extra : moz-landing-system : lando

layout/generic/nsGridContainerFrame.h

@@ -10,7 +10,6 @@
 #define nsGridContainerFrame_h___
 
 #include "mozilla/Maybe.h"
-#include "mozilla/TypeTraits.h"
 #include "mozilla/HashTable.h"
 #include "nsContainerFrame.h"
 

layout/generic/nsQueryFrame.h

@@ -7,9 +7,10 @@
 #ifndef nsQueryFrame_h
 #define nsQueryFrame_h
 
+#include <type_traits>
+
 #include "nscore.h"
 #include "mozilla/Assertions.h"
-#include "mozilla/TypeTraits.h"
 
 // NOTE: the long lines in this file are intentional to make compiler error
 // messages more readable.
@@ -126,9 +127,8 @@ class do_QueryFrameHelper {
   // downcasting is safe.
   template <class Src, class Dst>
   struct FastQueryFrame<
-      Src, Dst,
-      typename mozilla::EnableIf<std::is_base_of<nsIFrame, Src>::value>::Type,
-      typename mozilla::EnableIf<std::is_base_of<nsIFrame, Dst>::value>::Type> {
+      Src, Dst, std::enable_if_t<std::is_base_of<nsIFrame, Src>::value>,
+      std::enable_if_t<std::is_base_of<nsIFrame, Dst>::value>> {
     static Dst* QueryFrame(Src* aFrame) {
       return nsQueryFrame::FrameIID(aFrame->mClass) == Dst::kFrameIID
                  ? reinterpret_cast<Dst*>(aFrame)

layout/style/ServoUtils.h

@@ -10,7 +10,6 @@
 #define mozilla_ServoUtils_h
 
 #include "mozilla/Assertions.h"
-#include "mozilla/TypeTraits.h"
 #include "MainThreadUtils.h"
 
 namespace mozilla {

layout/style/nsCSSValue.h

@@ -105,8 +105,7 @@ class nsCSSValue {
   nsCSSValue(nsCSSValue&& aOther) : mUnit(aOther.mUnit), mValue(aOther.mValue) {
     aOther.mUnit = eCSSUnit_Null;
   }
-  template <typename T,
-            typename = typename std::enable_if<std::is_enum<T>::value>::type>
+  template <typename T, typename = std::enable_if_t<std::is_enum<T>::value>>
   explicit nsCSSValue(T aValue) : mUnit(eCSSUnit_Enumerated) {
     static_assert(mozilla::EnumTypeFitsWithin<T, int32_t>::value,
                   "aValue must be an enum that fits within mValue.mInt");
@@ -193,8 +192,7 @@ class nsCSSValue {
 
  public:
   void SetIntValue(int32_t aValue, nsCSSUnit aUnit);
-  template <typename T,
-            typename = typename std::enable_if<std::is_enum<T>::value>::type>
+  template <typename T, typename = std::enable_if_t<std::is_enum<T>::value>>
   void SetEnumValue(T aValue) {
     static_assert(mozilla::EnumTypeFitsWithin<T, int32_t>::value,
                   "aValue must be an enum that fits within mValue.mInt");