Bug 1461938 part 3 - Store JS::Realm* instead of JSCompartment* in ObjectGroup. r=luke

--HG--
extra : rebase_source : a569b3b066beea3cad4acb30ea8e8084e59763f7

js/src/gc/GC.cpp

@@ -8056,7 +8056,7 @@ GCRuntime::mergeCompartments(JSCompartment* source, JSCompartment* target)
         }
 
         group->setGeneration(target->zone()->types.generation);
-        group->compartment_ = target;
+        group->realm_ = JS::GetRealmForCompartment(target);
 
         // Remove any unboxed layouts from the list in the off thread
         // compartment. These do not need to be reinserted in the target

js/src/jit/MacroAssembler.cpp

@@ -3275,7 +3275,7 @@ MacroAssembler::branchTestObjCompartment(Condition cond, Register obj, const Add
 {
     MOZ_ASSERT(obj != scratch);
     loadPtr(Address(obj, JSObject::offsetOfGroup()), scratch);
-    loadPtr(Address(scratch, ObjectGroup::offsetOfCompartment()), scratch);
+    loadPtr(Address(scratch, ObjectGroup::offsetOfRealm()), scratch);
     branchPtr(cond, compartment, scratch, label);
 }
 
@@ -3286,7 +3286,7 @@ MacroAssembler::branchTestObjCompartment(Condition cond, Register obj,
 {
     MOZ_ASSERT(obj != scratch);
     loadPtr(Address(obj, JSObject::offsetOfGroup()), scratch);
-    loadPtr(Address(scratch, ObjectGroup::offsetOfCompartment()), scratch);
+    loadPtr(Address(scratch, ObjectGroup::offsetOfRealm()), scratch);
     branchPtr(cond, scratch, ImmPtr(compartment), label);
 }
 

js/src/vm/JSObject.h

@@ -162,6 +162,7 @@ class JSObject : public js::gc::Cell
 
     JSCompartment* compartment() const { return group_->compartment(); }
     JSCompartment* maybeCompartment() const { return compartment(); }
+    JS::Realm* realm() const { return group_->realm(); }
 
     inline js::Shape* maybeShape() const;
     inline js::Shape* ensureShape(JSContext* cx);

js/src/vm/ObjectGroup.cpp

@@ -34,7 +34,7 @@ using mozilla::PodZero;
 // ObjectGroup
 /////////////////////////////////////////////////////////////////////
 
-ObjectGroup::ObjectGroup(const Class* clasp, TaggedProto proto, JSCompartment* comp,
+ObjectGroup::ObjectGroup(const Class* clasp, TaggedProto proto, JS::Realm* realm,
                          ObjectGroupFlags initialFlags)
 {
     PodZero(this);
@@ -45,7 +45,7 @@ ObjectGroup::ObjectGroup(const Class* clasp, TaggedProto proto, JSCompartment* c
 
     this->clasp_ = clasp;
     this->proto_ = proto;
-    this->compartment_ = comp;
+    this->realm_ = realm;
     this->flags_ = initialFlags;
 
     setGeneration(zone()->types.generation);
@@ -1673,7 +1673,7 @@ ObjectGroupCompartment::makeGroup(JSContext* cx, const Class* clasp,
     ObjectGroup* group = Allocate<ObjectGroup>(cx);
     if (!group)
         return nullptr;
-    new(group) ObjectGroup(clasp, proto, cx->compartment(), initialFlags);
+    new(group) ObjectGroup(clasp, proto, cx->realm(), initialFlags);
 
     return group;
 }

js/src/vm/ObjectGroup.h

@@ -96,8 +96,8 @@ class ObjectGroup : public gc::TenuredCell
     /* Prototype shared by objects in this group. */
     GCPtr<TaggedProto> proto_;
 
-    /* Compartment shared by objects in this group. */
-    JSCompartment* compartment_;
+    /* Realm shared by objects in this group. */
+    JS::Realm* realm_;
 
   public:
     const Class* clasp() const {
@@ -152,8 +152,9 @@ class ObjectGroup : public gc::TenuredCell
         return res;
     }
 
-    JSCompartment* compartment() const { return compartment_; }
+    JSCompartment* compartment() const { return JS::GetCompartmentForRealm(realm_); }
     JSCompartment* maybeCompartment() const { return compartment(); }
+    JS::Realm* realm() const { return realm_; }
 
   private:
     /* Flags for this group. */
@@ -377,7 +378,7 @@ class ObjectGroup : public gc::TenuredCell
     Property** propertySet;
   public:
 
-    inline ObjectGroup(const Class* clasp, TaggedProto proto, JSCompartment* comp,
+    inline ObjectGroup(const Class* clasp, TaggedProto proto, JS::Realm* realm,
                        ObjectGroupFlags initialFlags);
 
     inline bool hasAnyFlags(const AutoSweepObjectGroup& sweep, ObjectGroupFlags flags);
@@ -475,8 +476,8 @@ class ObjectGroup : public gc::TenuredCell
         return offsetof(ObjectGroup, proto_);
     }
 
-    static inline uint32_t offsetOfCompartment() {
-        return offsetof(ObjectGroup, compartment_);
+    static inline uint32_t offsetOfRealm() {
+        return offsetof(ObjectGroup, realm_);
     }
 
     static inline uint32_t offsetOfAddendum() {