diff --git a/js/src/gc/RootMarking.cpp b/js/src/gc/RootMarking.cpp
index 1206acaddd3..86cc2b5c38f 100644
--- a/js/src/gc/RootMarking.cpp
+++ b/js/src/gc/RootMarking.cpp
@@ -531,6 +531,17 @@ AutoGCRooter::trace(JSTracer *trc)
         return;
       }
 
+      case OBJOBJHASHMAP: {
+        AutoObjectObjectHashMap::HashMapImpl &map = static_cast<AutoObjectObjectHashMap *>(this)->map;
+        for (AutoObjectObjectHashMap::Enum e(map); !e.empty(); e.popFront()) {
+            RawObject key = e.front().key;
+            MarkObjectRoot(trc, (RawObject *) &e.front().key, "AutoObjectObjectHashMap key");
+            JS_ASSERT(key == e.front().key);
+            MarkObjectRoot(trc, &e.front().value, "AutoObjectObjectHashMap value");
+        }
+        return;
+      }
+
       case PROPDESC: {
         PropDesc::AutoRooter *rooter = static_cast<PropDesc::AutoRooter *>(this);
         MarkValueRoot(trc, &rooter->pd->pd_, "PropDesc::AutoRooter pd");
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 552acfda05c..0ed16a1b1b6 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -31,6 +31,7 @@
 
 #include "jsalloc.h"
 #include "js/Vector.h"
+#include "js/HashTable.h"
 
 /************************************************************************/
 
@@ -1041,7 +1042,7 @@ class JS_PUBLIC_API(AutoGCRooter) {
         *stackTop = down;
     }
 
-    /* Implemented in jsgc.cpp. */
+    /* Implemented in gc/RootMarking.cpp. */
     inline void trace(JSTracer *trc);
     static void traceAll(JSTracer *trc);
     static void traceAllWrappers(JSTracer *trc);
@@ -1087,7 +1088,8 @@ class JS_PUBLIC_API(AutoGCRooter) {
         IONMASM =     -28, /* js::ion::MacroAssembler */
         IONALLOC =    -29, /* js::ion::AutoTempAllocatorRooter */
         WRAPVECTOR =  -30, /* js::AutoWrapperVector */
-        WRAPPER =     -31  /* js::AutoWrapperRooter */
+        WRAPPER =     -31, /* js::AutoWrapperRooter */
+        OBJOBJHASHMAP=-32  /* js::AutoObjectObjectHashMap */
     };
 
   private:
@@ -1328,6 +1330,129 @@ class AutoVectorRooter : protected AutoGCRooter
     JS_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
+template<class Key, class Value>
+class AutoHashMapRooter : protected AutoGCRooter
+{
+  private:
+    typedef js::HashMap<Key, Value> HashMapImpl;
+
+  public:
+    explicit AutoHashMapRooter(JSContext *cx, ptrdiff_t tag
+                               JS_GUARD_OBJECT_NOTIFIER_PARAM)
+      : AutoGCRooter(cx, tag), map(cx)
+    {
+        JS_GUARD_OBJECT_NOTIFIER_INIT;
+    }
+
+    typedef Key KeyType;
+    typedef Value ValueType;
+    typedef typename HashMapImpl::Lookup Lookup;
+    typedef typename HashMapImpl::Ptr Ptr;
+    typedef typename HashMapImpl::AddPtr AddPtr;
+
+    bool init(uint32_t len = 16) {
+        return map.init(len);
+    }
+    bool initialized() const {
+        return map.initialized();
+    }
+    Ptr lookup(const Lookup &l) const {
+        return map.lookup(l);
+    }
+    void remove(Ptr p) {
+        map.remove(p);
+    }
+    AddPtr lookupForAdd(const Lookup &l) const {
+        return map.lookupForAdd(l);
+    }
+
+    template<typename KeyInput, typename ValueInput>
+    bool add(AddPtr &p, const KeyInput &k, const ValueInput &v) {
+        return map.add(k, v);
+    }
+
+    bool add(AddPtr &p, const Key &k) {
+        return map.add(p, k);
+    }
+
+    template<typename KeyInput, typename ValueInput>
+    bool relookupOrAdd(AddPtr &p, const KeyInput &k, const ValueInput &v) {
+        return map.relookupOrAdd(p, k, v);
+    }
+
+    typedef typename HashMapImpl::Range Range;
+    Range all() const {
+        return map.all();
+    }
+
+    typedef typename HashMapImpl::Enum Enum;
+
+    void clear() {
+        map.clear();
+    }
+
+    void finish() {
+        map.finish();
+    }
+
+    bool empty() const {
+        return map.empty();
+    }
+
+    uint32_t count() const {
+        return map.count();
+    }
+
+    size_t capacity() const {
+        return map.capacity();
+    }
+
+    size_t sizeOfExcludingThis(JSMallocSizeOfFun mallocSizeOf) const {
+        return map.sizeOfExcludingThis(mallocSizeOf);
+    }
+    size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf) const {
+        return map.sizeOfIncludingThis(mallocSizeOf);
+    }
+
+    unsigned generation() const {
+        return map.generation();
+    }
+
+    /************************************************** Shorthand operations */
+
+    bool has(const Lookup &l) const {
+        return map.has(l);
+    }
+
+    template<typename KeyInput, typename ValueInput>
+    bool put(const KeyInput &k, const ValueInput &v) {
+        return map.put(k, v);
+    }
+
+    template<typename KeyInput, typename ValueInput>
+    bool putNew(const KeyInput &k, const ValueInput &v) {
+        return map.putNew(k, v);
+    }
+
+    Ptr lookupWithDefault(const Key &k, const Value &defaultValue) {
+        return map.lookupWithDefault(k, defaultValue);
+    }
+
+    void remove(const Lookup &l) {
+        map.remove(l);
+    }
+
+    friend void AutoGCRooter::trace(JSTracer *trc);
+
+  private:
+    AutoHashMapRooter(const AutoHashMapRooter &hmr) MOZ_DELETE;
+    AutoHashMapRooter &operator=(const AutoHashMapRooter &hmr) MOZ_DELETE;
+
+    HashMapImpl map;
+
+    JS_DECL_USE_GUARD_OBJECT_NOTIFIER
+};
+
 class AutoValueVector : public AutoVectorRooter<Value>
 {
   public:
diff --git a/js/src/jscntxt.h b/js/src/jscntxt.h
index 591ecb3dd31..511c2e9cc7a 100644
--- a/js/src/jscntxt.h
+++ b/js/src/jscntxt.h
@@ -2097,12 +2097,12 @@ SetValueRangeToNull(Value *vec, size_t len)
     SetValueRangeToNull(vec, vec + len);
 }
 
-class AutoObjectVector : public AutoVectorRooter<JSObject *>
+class AutoObjectVector : public AutoVectorRooter<RawObject>
 {
   public:
     explicit AutoObjectVector(JSContext *cx
                               JS_GUARD_OBJECT_NOTIFIER_PARAM)
-        : AutoVectorRooter<JSObject *>(cx, OBJVECTOR)
+        : AutoVectorRooter<RawObject>(cx, OBJVECTOR)
     {
         JS_GUARD_OBJECT_NOTIFIER_INIT;
     }
@@ -2110,12 +2110,12 @@ class AutoObjectVector : public AutoVectorRooter<JSObject *>
     JS_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class AutoStringVector : public AutoVectorRooter<JSString *>
+class AutoStringVector : public AutoVectorRooter<RawString>
 {
   public:
     explicit AutoStringVector(JSContext *cx
                               JS_GUARD_OBJECT_NOTIFIER_PARAM)
-        : AutoVectorRooter<JSString *>(cx, STRINGVECTOR)
+        : AutoVectorRooter<RawString>(cx, STRINGVECTOR)
     {
         JS_GUARD_OBJECT_NOTIFIER_INIT;
     }
@@ -2123,12 +2123,12 @@ class AutoStringVector : public AutoVectorRooter<JSString *>
     JS_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-class AutoShapeVector : public AutoVectorRooter<Shape *>
+class AutoShapeVector : public AutoVectorRooter<RawShape>
 {
   public:
     explicit AutoShapeVector(JSContext *cx
                              JS_GUARD_OBJECT_NOTIFIER_PARAM)
-        : AutoVectorRooter<Shape *>(cx, SHAPEVECTOR)
+        : AutoVectorRooter<RawShape>(cx, SHAPEVECTOR)
     {
         JS_GUARD_OBJECT_NOTIFIER_INIT;
     }
@@ -2138,24 +2138,37 @@ class AutoShapeVector : public AutoVectorRooter<Shape *>
 
 class AutoValueArray : public AutoGCRooter
 {
-    js::Value *start_;
+    RawValue *start_;
     unsigned length_;
     SkipRoot skip;
 
   public:
-    AutoValueArray(JSContext *cx, js::Value *start, unsigned length
+    AutoValueArray(JSContext *cx, RawValue *start, unsigned length
                    JS_GUARD_OBJECT_NOTIFIER_PARAM)
       : AutoGCRooter(cx, VALARRAY), start_(start), length_(length), skip(cx, start, length)
     {
         JS_GUARD_OBJECT_NOTIFIER_INIT;
     }
 
-    Value *start() { return start_; }
+    RawValue *start() { return start_; }
     unsigned length() const { return length_; }
 
     JS_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
+class AutoObjectObjectHashMap : public AutoHashMapRooter<RawObject, RawObject>
+{
+  public:
+    explicit AutoObjectObjectHashMap(JSContext *cx
+                                     JS_GUARD_OBJECT_NOTIFIER_PARAM)
+      : AutoHashMapRooter<RawObject, RawObject>(cx, OBJOBJHASHMAP)
+    {
+        JS_GUARD_OBJECT_NOTIFIER_INIT;
+    }
+
+    JS_DECL_USE_GUARD_OBJECT_NOTIFIER
+};
+
 /*
  * Allocation policy that uses JSRuntime::malloc_ and friends, so that
  * memory pressure is properly accounted for. This is suitable for