diff -r 000000000000 -r 6474c204b198 js/src/vm/DateObject.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/vm/DateObject.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#ifndef vm_DateObject_h_
+#define vm_DateObject_h_
+
+#include "jsobj.h"
+
+#include "js/Value.h"
+
+namespace js {
+
+class DateTimeInfo;
+
+class DateObject : public JSObject
+{
+    static const uint32_t UTC_TIME_SLOT = 0;
+    static const uint32_t TZA_SLOT = 1;
+
+    /*
+     * Cached slots holding local properties of the date.
+     * These are undefined until the first actual lookup occurs
+     * and are reset to undefined whenever the date's time is modified.
+     */
+    static const uint32_t COMPONENTS_START_SLOT = 2;
+
+    static const uint32_t LOCAL_TIME_SLOT    = COMPONENTS_START_SLOT + 0;
+    static const uint32_t LOCAL_YEAR_SLOT    = COMPONENTS_START_SLOT + 1;
+    static const uint32_t LOCAL_MONTH_SLOT   = COMPONENTS_START_SLOT + 2;
+    static const uint32_t LOCAL_DATE_SLOT    = COMPONENTS_START_SLOT + 3;
+    static const uint32_t LOCAL_DAY_SLOT     = COMPONENTS_START_SLOT + 4;
+    static const uint32_t LOCAL_HOURS_SLOT   = COMPONENTS_START_SLOT + 5;
+    static const uint32_t LOCAL_MINUTES_SLOT = COMPONENTS_START_SLOT + 6;
+    static const uint32_t LOCAL_SECONDS_SLOT = COMPONENTS_START_SLOT + 7;
+
+    static const uint32_t RESERVED_SLOTS = LOCAL_SECONDS_SLOT + 1;
+
+  public:
+    static const Class class_;
+
+    inline const js::Value &UTCTime() const {
+        return getFixedSlot(UTC_TIME_SLOT);
+    }
+
+    // Set UTC time to a given time and invalidate cached local time.
+    void setUTCTime(double t, Value *vp = nullptr);
+
+    inline double cachedLocalTime(DateTimeInfo *dtInfo);
+
+    // Cache the local time, year, month, and so forth of the object.
+    // If UTC time is not finite (e.g., NaN), the local time
+    // slots will be set to the UTC time without conversion.
+    void fillLocalTimeSlots(DateTimeInfo *dtInfo);
+
+    static MOZ_ALWAYS_INLINE bool getTime_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getYear_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getFullYear_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCFullYear_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getMonth_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCMonth_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getDate_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCDate_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getDay_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCDay_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getHours_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCHours_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getMinutes_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCMinutes_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCSeconds_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getUTCMilliseconds_impl(JSContext *cx, CallArgs args);
+    static MOZ_ALWAYS_INLINE bool getTimezoneOffset_impl(JSContext *cx, CallArgs args);
+};
+
+} // namespace js
+
+#endif // vm_DateObject_h_