Rename the MozMap C++ type to "record" and give it a template parameter for the key type

7 files changed, 145 insertions, 126 deletions

diff --git a/dom/bindings/BindingUtils.h b/dom/bindings/BindingUtils.h
index 23bbbea5a..e017b986a 100644
--- a/dom/bindings/BindingUtils.h
+++ b/dom/bindings/BindingUtils.h
@@ -49,7 +49,7 @@ namespace mozilla {
 enum UseCounter : int16_t;
 
 namespace dom {
-template<typename DataType> class MozMap;
+template<typename KeyType, typename ValueType> class Record;
 
 nsresult
 UnwrapArgImpl(JS::Handle<JSObject*> src, const nsIID& iid, void** ppArg);
@@ -2293,25 +2293,26 @@ public:
   }
 };
 
-template<typename T>
-void TraceMozMap(JSTracer* trc, MozMap<T>& map)
+template<typename K, typename V>
+void TraceRecord(JSTracer* trc, Record<K, V>& record)
 {
-  for (auto& entry : map.Entries()) {
+  for (auto& entry : record.Entries()) {
     // Act like it's a one-element sequence to leverage all that infrastructure.
-    SequenceTracer<T>::TraceSequence(trc, &entry.mValue, &entry.mValue + 1);
+    SequenceTracer<V>::TraceSequence(trc, &entry.mValue, &entry.mValue + 1);
   }
 }
 
-// sequence<MozMap>
-template<typename T>
-class SequenceTracer<MozMap<T>, false, false, false>
+// sequence<record>
+template<typename K, typename V>
+class SequenceTracer<Record<K, V>, false, false, false>
 {
   explicit SequenceTracer() = delete; // Should never be instantiated
 
 public:
-  static void TraceSequence(JSTracer* trc, MozMap<T>* seqp, MozMap<T>* end) {
+  static void TraceSequence(JSTracer* trc, Record<K, V>* seqp,
+                            Record<K, V>* end) {
     for (; seqp != end; ++seqp) {
-      TraceMozMap(trc, *seqp);
+      TraceRecord(trc, *seqp);
     }
   }
 };
@@ -2389,51 +2390,51 @@ public:
   SequenceType mSequenceType;
 };
 
-// Rooter class for MozMap; this is what we mostly use in the codegen.
-template<typename T>
-class MOZ_RAII MozMapRooter final : private JS::CustomAutoRooter
+// Rooter class for Record; this is what we mostly use in the codegen.
+template<typename K, typename V>
+class MOZ_RAII RecordRooter final : private JS::CustomAutoRooter
 {
 public:
-  MozMapRooter(JSContext *aCx, MozMap<T>* aMozMap
+  RecordRooter(JSContext *aCx, Record<K, V>* aRecord
                MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
     : JS::CustomAutoRooter(aCx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
-      mMozMap(aMozMap),
-      mMozMapType(eMozMap)
+      mRecord(aRecord),
+      mRecordType(eRecord)
   {
   }
 
-  MozMapRooter(JSContext *aCx, Nullable<MozMap<T>>* aMozMap
+  RecordRooter(JSContext *aCx, Nullable<Record<K, V>>* aRecord
                  MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
     : JS::CustomAutoRooter(aCx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
-      mNullableMozMap(aMozMap),
-      mMozMapType(eNullableMozMap)
+      mNullableRecord(aRecord),
+      mRecordType(eNullableRecord)
   {
   }
 
 private:
-  enum MozMapType {
-    eMozMap,
-    eNullableMozMap
+  enum RecordType {
+    eRecord,
+    eNullableRecord
   };
 
   virtual void trace(JSTracer *trc) override
   {
-    if (mMozMapType == eMozMap) {
-      TraceMozMap(trc, *mMozMap);
+    if (mRecordType == eRecord) {
+      TraceRecord(trc, *mRecord);
     } else {
-      MOZ_ASSERT(mMozMapType == eNullableMozMap);
-      if (!mNullableMozMap->IsNull()) {
-        TraceMozMap(trc, mNullableMozMap->Value());
+      MOZ_ASSERT(mRecordType == eNullableRecord);
+      if (!mNullableRecord->IsNull()) {
+        TraceRecord(trc, mNullableRecord->Value());
       }
     }
   }
 
   union {
-    MozMap<T>* mMozMap;
-    Nullable<MozMap<T>>* mNullableMozMap;
+    Record<K, V>* mRecord;
+    Nullable<Record<K, V>>* mNullableRecord;
   };
 
-  MozMapType mMozMapType;
+  RecordType mRecordType;
 };
 
 template<typename T>
diff --git a/dom/bindings/Codegen.py b/dom/bindings/Codegen.py
index d7212f7bd..ff6fa0ea3 100644
--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -996,6 +996,8 @@ class CGElseChain(CGThing):
 
 class CGTemplatedType(CGWrapper):
     def __init__(self, templateName, child, isConst=False, isReference=False):
+        if isinstance(child, list):
+            child = CGList(child, ", ")
         const = "const " if isConst else ""
         pre = "%s%s<" % (const, templateName)
         ref = "&" if isReference else ""
@@ -1173,10 +1175,10 @@ class CGHeaders(CGWrapper):
                 bindingHeaders.add("mozilla/dom/PrimitiveConversions.h")
             elif unrolled.isRecord():
                 if dictionary or jsImplementedDescriptors:
-                    declareIncludes.add("mozilla/dom/MozMap.h")
+                    declareIncludes.add("mozilla/dom/Record.h")
                 else:
-                    bindingHeaders.add("mozilla/dom/MozMap.h")
-                # Also add headers for the type the MozMap is
+                    bindingHeaders.add("mozilla/dom/Record.h")
+                # Also add headers for the type the record is
                 # parametrized over, if needed.
                 addHeadersForType((t.inner, dictionary))
 
@@ -1389,7 +1391,7 @@ def UnionTypes(unionTypes, config):
                     # code.
                     headers.add(CGHeaders.getDeclarationFilename(f.callback))
                 elif f.isRecord():
-                    headers.add("mozilla/dom/MozMap.h")
+                    headers.add("mozilla/dom/Record.h")
                     # And add headers for the type we're parametrized over
                     addHeadersForType(f.inner)
 
@@ -1449,8 +1451,8 @@ def UnionConversions(unionTypes, config):
                 elif f.isPrimitive():
                     headers.add("mozilla/dom/PrimitiveConversions.h")
                 elif f.isRecord():
-                    headers.add("mozilla/dom/MozMap.h")
-                    # And the internal type of the MozMap
+                    headers.add("mozilla/dom/Record.h")
+                    # And the internal type of the record
                     addHeadersForType(f.inner)
 
             # We plan to include UnionTypes.h no matter what, so it's
@@ -4370,6 +4372,13 @@ def handleDefaultStringValue(defaultValue, method):
             }
 
 
+def recordKeyDeclType(recordType):
+    assert recordType.keyType.isString()
+    if recordType.keyType.isByteString():
+        return CGGeneric("nsCString")
+    return CGGeneric("nsString")
+
+
 # If this function is modified, modify CGNativeMember.getArg and
 # CGNativeMember.getRetvalInfo accordingly.  The latter cares about the decltype
 # and holdertype we end up using, because it needs to be able to return the code
@@ -4564,7 +4573,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
             declArgs = "cx"
         else:
             assert (isMember in
-                    ("Sequence", "Variadic", "Dictionary", "OwningUnion", "MozMap"))
+                    ("Sequence", "Variadic", "Dictionary", "OwningUnion", "Record"))
             # We'll get traced by the sequence or dictionary or union tracer
             declType = CGGeneric("JSObject*")
             declArgs = None
@@ -4733,36 +4742,38 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
     if type.isRecord():
         assert not isEnforceRange and not isClamp
         if failureCode is None:
-            notMozMap = ('ThrowErrorMessage(cx, MSG_NOT_OBJECT, "%s");\n'
+            notRecord = ('ThrowErrorMessage(cx, MSG_NOT_OBJECT, "%s");\n'
                          "%s" % (firstCap(sourceDescription), exceptionCode))
         else:
-            notMozMap = failureCode
+            notRecord = failureCode
 
         nullable = type.nullable()
         # Be very careful not to change "type": we need it later
         if nullable:
-            valueType = type.inner.inner
+            recordType = type.inner
         else:
-            valueType = type.inner
+            recordType = type
+        valueType = recordType.inner
 
         valueInfo = getJSToNativeConversionInfo(
-            valueType, descriptorProvider, isMember="MozMap",
+            valueType, descriptorProvider, isMember="Record",
             exceptionCode=exceptionCode, lenientFloatCode=lenientFloatCode,
             isCallbackReturnValue=isCallbackReturnValue,
             sourceDescription="value in %s" % sourceDescription,
             nestingLevel=incrementNestingLevel())
         if valueInfo.dealWithOptional:
-            raise TypeError("Shouldn't have optional things in MozMap")
+            raise TypeError("Shouldn't have optional things in record")
         if valueInfo.holderType is not None:
-            raise TypeError("Shouldn't need holders for MozMap")
+            raise TypeError("Shouldn't need holders for record")
 
-        typeName = CGTemplatedType("MozMap", valueInfo.declType)
-        mozMapType = typeName.define()
+        declType = CGTemplatedType("Record", [recordKeyDeclType(recordType),
+                                              valueInfo.declType])
+        typeName = declType.define()
         if nullable:
-            typeName = CGTemplatedType("Nullable", typeName)
-            mozMapRef = "${declName}.SetValue()"
+            declType = CGTemplatedType("Nullable", declType)
+            recordRef = "${declName}.SetValue()"
         else:
-            mozMapRef = "${declName}"
+            recordRef = "${declName}"
 
         valueConversion = string.Template(valueInfo.template).substitute({
             "val": "temp",
@@ -4777,17 +4788,17 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
 
         templateBody = fill(
             """
-            auto& mozMapEntries = ${mozMapRef}.Entries();
+            auto& recordEntries = ${recordRef}.Entries();
 
-            JS::Rooted<JSObject*> mozMapObj(cx, &$${val}.toObject());
+            JS::Rooted<JSObject*> recordObj(cx, &$${val}.toObject());
             JS::AutoIdVector ids(cx);
             // Keep skipping symbols until
             // https://github.com/heycam/webidl/issues/294 is sorted out.
-            if (!js::GetPropertyKeys(cx, mozMapObj,
+            if (!js::GetPropertyKeys(cx, recordObj,
                                      JSITER_OWNONLY | JSITER_HIDDEN, &ids)) {
               $*{exceptionCode}
             }
-            if (!mozMapEntries.SetCapacity(ids.length(), mozilla::fallible)) {
+            if (!recordEntries.SetCapacity(ids.length(), mozilla::fallible)) {
               JS_ReportOutOfMemory(cx);
               $*{exceptionCode}
             }
@@ -4800,7 +4811,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
               MOZ_ASSERT(!JSID_IS_SYMBOL(curId), "No symbols, we said!");
 
               JS::Rooted<JS::PropertyDescriptor> desc(cx);
-              if (!JS_GetOwnPropertyDescriptorById(cx, mozMapObj, curId,
+              if (!JS_GetOwnPropertyDescriptorById(cx, recordObj, curId,
                                                    &desc)) {
                 $*{exceptionCode}
               }
@@ -4817,44 +4828,45 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
               }
               MOZ_ASSERT(!isSymbol, "We said, no symbols!");
 
-              if (!JS_GetPropertyById(cx, mozMapObj, curId, &temp)) {
+              if (!JS_GetPropertyById(cx, recordObj, curId, &temp)) {
                 $*{exceptionCode}
               }
 
               // Safe to do an infallible append here, because we did a
               // SetCapacity above to the right capacity.
-              ${mozMapType}::EntryType* entry = mozMapEntries.AppendElement();
+              ${typeName}::EntryType* entry = recordEntries.AppendElement();
               entry->mKey = propName;
               ${valueType}& slot = entry->mValue;
               $*{valueConversion}
             }
             """,
             exceptionCode=exceptionCode,
-            mozMapRef=mozMapRef,
-            mozMapType=mozMapType,
+            recordRef=recordRef,
+            typeName=typeName,
             valueType=valueInfo.declType.define(),
             valueConversion=valueConversion)
 
         templateBody = wrapObjectTemplate(templateBody, type,
                                           "${declName}.SetNull();\n",
-                                          notMozMap)
+                                          notRecord)
 
-        declType = typeName
         declArgs = None
         holderType = None
         holderArgs = None
-        # MozMap arguments that might contain traceable things need
+        # record arguments that might contain traceable things need
         # to get traced
         if not isMember and isCallbackReturnValue:
             # Go ahead and just convert directly into our actual return value
             declType = CGWrapper(declType, post="&")
             declArgs = "aRetVal"
         elif not isMember and typeNeedsRooting(valueType):
-            holderType = CGTemplatedType("MozMapRooter", valueInfo.declType)
-            # If our MozMap is nullable, this will set the Nullable to be
+            holderType = CGTemplatedType("RecordRooter",
+                                         [recordKeyDeclType(recordType),
+                                          valueInfo.declType])
+            # If our record is nullable, this will set the Nullable to be
             # not-null, but that's ok because we make an explicit SetNull() call
             # on it as needed if our JS value is actually null.
-            holderArgs = "cx, &%s" % mozMapRef
+            holderArgs = "cx, &%s" % recordRef
 
         return JSToNativeConversionInfo(templateBody, declType=declType,
                                         declArgs=declArgs,
@@ -4937,16 +4949,16 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
         else:
             setDictionary = None
 
-        mozMapMemberTypes = filter(lambda t: t.isRecord(), memberTypes)
-        if len(mozMapMemberTypes) > 0:
-            assert len(mozMapMemberTypes) == 1
-            name = getUnionMemberName(mozMapMemberTypes[0])
-            mozMapObject = CGGeneric(
+        recordMemberTypes = filter(lambda t: t.isRecord(), memberTypes)
+        if len(recordMemberTypes) > 0:
+            assert len(recordMemberTypes) == 1
+            name = getUnionMemberName(recordMemberTypes[0])
+            recordObject = CGGeneric(
                 "done = (failed = !%s.TrySetTo%s(cx, ${val}, tryNext, ${passedToJSImpl})) || !tryNext;\n" %
                 (unionArgumentObj, name))
             names.append(name)
         else:
-            mozMapObject = None
+            recordObject = None
 
         objectMemberTypes = filter(lambda t: t.isObject(), memberTypes)
         if len(objectMemberTypes) > 0:
@@ -4962,10 +4974,10 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
         else:
             object = None
 
-        hasObjectTypes = interfaceObject or sequenceObject or dateObject or callbackObject or object or mozMapObject
+        hasObjectTypes = interfaceObject or sequenceObject or dateObject or callbackObject or object or recordObject
         if hasObjectTypes:
             # "object" is not distinguishable from other types
-            assert not object or not (interfaceObject or sequenceObject or dateObject or callbackObject or mozMapObject)
+            assert not object or not (interfaceObject or sequenceObject or dateObject or callbackObject or recordObject)
             if sequenceObject or dateObject or callbackObject:
                 # An object can be both an sequence object and a callback or
                 # dictionary, but we shouldn't have both in the union's members
@@ -4985,9 +4997,9 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
             if dateObject:
                 templateBody.prepend(CGGeneric("JS::Rooted<JSObject*> argObj(cx, &${val}.toObject());\n"))
 
-            if mozMapObject:
+            if recordObject:
                 templateBody = CGList([templateBody,
-                                       CGIfWrapper(mozMapObject, "!done")])
+                                       CGIfWrapper(recordObject, "!done")])
 
             templateBody = CGIfWrapper(templateBody, "${val}.isObject()")
         else:
@@ -5747,7 +5759,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
         assert not isEnforceRange and not isClamp
 
         declArgs = None
-        if isMember in ("Variadic", "Sequence", "Dictionary", "MozMap"):
+        if isMember in ("Variadic", "Sequence", "Dictionary", "Record"):
             # Rooting is handled by the sequence and dictionary tracers.
             declType = "JS::Value"
         else:
@@ -6280,7 +6292,7 @@ def getMaybeWrapValueFuncForType(type):
 
 
 sequenceWrapLevel = 0
-mozMapWrapLevel = 0
+recordWrapLevel = 0
 
 
 def getWrapTemplateForType(type, descriptorProvider, result, successCode,
@@ -6459,13 +6471,13 @@ def getWrapTemplateForType(type, descriptorProvider, result, successCode,
         return (code, False)
 
     if type.isRecord():
-        # Now do non-nullable MozMap.  Our success code is just to break to
+        # Now do non-nullable record.  Our success code is just to break to
         # where we define the property on the object.  Note that we bump the
-        # mozMapWrapLevel around this call so that nested MozMap conversions
+        # recordWrapLevel around this call so that nested record conversions
         # will use different temp value names.
-        global mozMapWrapLevel
-        valueName = "mozMapValue%d" % mozMapWrapLevel
-        mozMapWrapLevel += 1
+        global recordWrapLevel
+        valueName = "recordValue%d" % recordWrapLevel
+        recordWrapLevel += 1
         innerTemplate = wrapForType(
             type.inner, descriptorProvider,
             {
@@ -6478,7 +6490,7 @@ def getWrapTemplateForType(type, descriptorProvider, result, successCode,
                 'obj': "returnObj",
                 'typedArraysAreStructs': typedArraysAreStructs
             })
-        mozMapWrapLevel -= 1
+        recordWrapLevel -= 1
         code = fill(
             """
 
@@ -6895,14 +6907,15 @@ def getRetvalDeclarationForType(returnType, descriptorProvider,
             returnType = returnType.inner
         result, _, _, _, _ = getRetvalDeclarationForType(returnType.inner,
                                                          descriptorProvider,
-                                                         isMember="MozMap")
+                                                         isMember="Record")
         # While we have our inner type, set up our rooter, if needed
         if not isMember and typeNeedsRooting(returnType):
-            rooter = CGGeneric("MozMapRooter<%s> resultRooter(cx, &result);\n" %
-                               result.define())
+            rooter = CGGeneric("RecordRooter<%s> resultRooter(cx, &result);\n" %
+                               ("nsString, " + result.define()))
         else:
             rooter = None
-        result = CGTemplatedType("MozMap", result)
+        result = CGTemplatedType("Record", [recordKeyDeclType(returnType),
+                                            result])
         if nullable:
             result = CGTemplatedType("Nullable", result)
         return result, "ref", rooter, None, None
@@ -7161,7 +7174,7 @@ class MethodNotNewObjectError(Exception):
 # nested sequences we don't use the same variable name to iterate over
 # different sequences.
 sequenceWrapLevel = 0
-mapWrapLevel = 0
+recordWrapLevel = 0
 
 
 def wrapTypeIntoCurrentCompartment(type, value, isMember=True):
@@ -7226,20 +7239,20 @@ def wrapTypeIntoCurrentCompartment(type, value, isMember=True):
         origType = type
         if type.nullable():
             type = type.inner
-            mozMapRef = "%s.Value()" % value
+            recordRef = "%s.Value()" % value
         else:
-            mozMapRef = value
-        global mapWrapLevel
-        entryRef = "mapEntry%d" % mapWrapLevel
-        mapWrapLevel += 1
+            recordRef = value
+        global recordWrapLevel
+        entryRef = "mapEntry%d" % recordWrapLevel
+        recordWrapLevel += 1
         wrapElement = wrapTypeIntoCurrentCompartment(type.inner,
                                                      "%s.mValue" % entryRef)
-        mapWrapLevel -= 1
+        recordWrapLevel -= 1
         if not wrapElement:
             return None
         wrapCode = CGWrapper(CGIndenter(wrapElement),
                              pre=("for (auto& %s : %s.Entries()) {\n" %
-                                  (entryRef, mozMapRef)),
+                                  (entryRef, recordRef)),
                              post="}\n")
         if origType.nullable():
             wrapCode = CGIfWrapper(wrapCode, "!%s.IsNull()" % value)
@@ -8131,7 +8144,7 @@ class CGMethodCall(CGThing):
                               if distinguishingType(s).isSequence())
 
             # Now append all the overloads that take a dictionary or callback
-            # interface or MozMap.  There should be only one of these!
+            # interface or record.  There should be only one of these!
             genericObjectSigs = [
                 s for s in possibleSignatures
                 if (distinguishingType(s).isDictionary() or
@@ -9694,13 +9707,18 @@ def getUnionAccessorSignatureType(type, descriptorProvider):
         if type.isSequence():
             wrapperType = "Sequence"
         else:
-            wrapperType = "MozMap"
+            wrapperType = "Record"
         # We don't use the returned template here, so it's OK to just pass no
         # sourceDescription.
         elementInfo = getJSToNativeConversionInfo(type.inner,
                                                   descriptorProvider,
                                                   isMember=wrapperType)
-        return CGTemplatedType(wrapperType, elementInfo.declType,
+        if wrapperType == "Sequence":
+            innerType = elementInfo.declType
+        else:
+            innerType = [recordKeyDeclType(type), elementInfo.declType]
+
+        return CGTemplatedType(wrapperType, innerType,
                                isConst=True, isReference=True)
 
     # Nested unions are unwrapped automatically into our flatMemberTypes.
@@ -10064,7 +10082,7 @@ class CGUnionStruct(CGThing):
                 elif t.isRecord():
                     traceCases.append(
                         CGCase("e" + vars["name"],
-                               CGGeneric("TraceMozMap(trc, mValue.m%s.Value());\n" %
+                               CGGeneric("TraceRecord(trc, mValue.m%s.Value());\n" %
                                          vars["name"])))
                 else:
                     assert t.isSpiderMonkeyInterface()
@@ -13194,7 +13212,7 @@ class CGDictionary(CGThing):
             if type.nullable():
                 trace = CGIfWrapper(trace, "!%s.IsNull()" % memberNullable)
         elif type.isRecord():
-            # If you implement this, add a MozMap<object> to
+            # If you implement this, add a record<DOMString, object> to
             # TestInterfaceJSDictionary and test it in test_bug1036214.html
             # to make sure we end up with the correct security properties.
             assert False
@@ -14111,8 +14129,8 @@ class CGNativeMember(ClassMethod):
                 returnCode = "aRetVal.SwapElements(${declName});\n"
             return "void", "", returnCode
         if type.isRecord():
-            # If we want to handle MozMap-of-MozMap return values, we're
-            # going to need to fix example codegen to not produce MozMap<void>
+            # If we want to handle record-of-record return values, we're
+            # going to need to fix example codegen to not produce record<void>
             # for the relevant argument...
             assert not isMember
             # In this case we convert directly into our outparam to start with
@@ -14166,7 +14184,8 @@ class CGNativeMember(ClassMethod):
                 returnType = returnType.inner
             # And now the actual underlying type
             elementDecl = self.getReturnType(returnType.inner, True)
-            type = CGTemplatedType("MozMap", CGGeneric(elementDecl))
+            type = CGTemplatedType("Record", [recordKeyDeclType(returnType),
+                                              CGGeneric(elementDecl)])
             if nullable:
                 type = CGTemplatedType("Nullable", type)
             args.append(Argument("%s&" % type.define(), "aRetVal"))
@@ -14227,7 +14246,7 @@ class CGNativeMember(ClassMethod):
         Nullable as needed.
 
         isMember can be false or one of the strings "Sequence", "Variadic",
-                 "MozMap"
+                 "Record"
         """
         if type.isSequence():
             nullable = type.nullable()
@@ -14243,8 +14262,8 @@ class CGNativeMember(ClassMethod):
             if nullable:
                 type = type.inner
             elementType = type.inner
-            argType = self.getArgType(elementType, False, "MozMap")[0]
-            decl = CGTemplatedType("MozMap", argType)
+            argType = self.getArgType(elementType, False, "Record")[0]
+            decl = CGTemplatedType("Record", [recordKeyDeclType(type), argType])
             return decl.define(), True, True
 
         if type.isUnion():
diff --git a/dom/bindings/MozMap.h b/dom/bindings/MozMap.h
index 2725c74ff..2fe18be2b 100644
--- a/dom/bindings/MozMap.h
+++ b/dom/bindings/MozMap.h
@@ -5,11 +5,11 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /**
- * Class for representing MozMap arguments.  Basically an array under the hood.
+ * Class for representing record arguments.  Basically an array under the hood.
  */
 
-#ifndef mozilla_dom_MozMap_h
-#define mozilla_dom_MozMap_h
+#ifndef mozilla_dom_Record_h
+#define mozilla_dom_Record_h
 
 #include "nsTHashtable.h"
 #include "nsHashKeys.h"
@@ -23,15 +23,15 @@ namespace dom {
 
 namespace binding_detail {
 template<typename KeyType, typename ValueType>
-class MozMapEntry
+class RecordEntry
 {
 public:
-  MozMapEntry()
+  RecordEntry()
   {
   }
 
-  // Move constructor so we can do MozMaps of MozMaps.
-  MozMapEntry(MozMapEntry<KeyType, ValueType>&& aOther)
+  // Move constructor so we can do Records of Records.
+  RecordEntry(RecordEntry<KeyType, ValueType>&& aOther)
     : mKey(Move(aOther.mKey)),
       mValue(Move(aOther.mValue))
   {
@@ -43,20 +43,19 @@ public:
 
 } // namespace binding_detail
 
-template<typename ValueType>
-class MozMap
+template<typename KeyType, typename ValueType>
+class Record
 {
 public:
-  typedef nsString KeyType;
-  typedef typename binding_detail::MozMapEntry<KeyType, ValueType> EntryType;
-  typedef MozMap<ValueType> SelfType;
+  typedef typename binding_detail::RecordEntry<nsString, ValueType> EntryType;
+  typedef Record<KeyType, ValueType> SelfType;
 
-  MozMap()
+  Record()
   {
   }
 
-  // Move constructor so we can do MozMap of MozMap.
-  MozMap(SelfType&& aOther) :
+  // Move constructor so we can do Record of Record.
+  Record(SelfType&& aOther) :
     mEntries(Move(aOther.mEntries))
   {
   }
@@ -78,4 +77,4 @@ private:
 } // namespace dom
 } // namespace mozilla
 
-#endif // mozilla_dom_MozMap_h
+#endif // mozilla_dom_Record_h
diff --git a/dom/bindings/moz.build b/dom/bindings/moz.build
index f1ce9e276..7e1358e9c 100644
--- a/dom/bindings/moz.build
+++ b/dom/bindings/moz.build
@@ -32,10 +32,10 @@ EXPORTS.mozilla.dom += [
     'FakeString.h',
     'IterableIterator.h',
     'JSSlots.h',
-    'MozMap.h',
     'NonRefcountedDOMObject.h',
     'Nullable.h',
     'PrimitiveConversions.h',
+    'Record.h',
     'RootedDictionary.h',
     'SimpleGlobalObject.h',
     'StructuredClone.h',
diff --git a/dom/fetch/Headers.h b/dom/fetch/Headers.h
index 38b0fc68f..1dd92f779 100644
--- a/dom/fetch/Headers.h
+++ b/dom/fetch/Headers.h
@@ -20,7 +20,7 @@ class ErrorResult;
 
 namespace dom {
 
-template<typename T> class MozMap;
+template<typename K, typename V> class Record;
 class HeadersOrByteStringSequenceSequenceOrByteStringByteStringRecord;
 class OwningHeadersOrByteStringSequenceSequenceOrByteStringByteStringRecord;
 
diff --git a/dom/fetch/InternalHeaders.cpp b/dom/fetch/InternalHeaders.cpp
index 83a686785..7bf5703dc 100644
--- a/dom/fetch/InternalHeaders.cpp
+++ b/dom/fetch/InternalHeaders.cpp
@@ -314,7 +314,7 @@ InternalHeaders::Fill(const Sequence<Sequence<nsCString>>& aInit, ErrorResult& a
 }
 
 void
-InternalHeaders::Fill(const MozMap<nsCString>& aInit, ErrorResult& aRv)
+InternalHeaders::Fill(const Record<nsCString, nsCString>& aInit, ErrorResult& aRv)
 {
   for (auto& entry : aInit.Entries()) {
     Append(NS_ConvertUTF16toUTF8(entry.mKey), entry.mValue, aRv);
diff --git a/dom/fetch/InternalHeaders.h b/dom/fetch/InternalHeaders.h
index 9a6d6dae7..98046f0ef 100644
--- a/dom/fetch/InternalHeaders.h
+++ b/dom/fetch/InternalHeaders.h
@@ -20,7 +20,7 @@ class ErrorResult;
 
 namespace dom {
 
-template<typename T> class MozMap;
+template<typename K, typename V> class Record;
 class HeadersEntry;
 
 class InternalHeaders final
@@ -113,7 +113,7 @@ public:
 
   void Fill(const InternalHeaders& aInit, ErrorResult& aRv);
   void Fill(const Sequence<Sequence<nsCString>>& aInit, ErrorResult& aRv);
-  void Fill(const MozMap<nsCString>& aInit, ErrorResult& aRv);
+  void Fill(const Record<nsCString, nsCString>& aInit, ErrorResult& aRv);
 
   bool HasOnlySimpleHeaders() const;