From 3d2f44a932796e91c287d51e493970e14f577619 Mon Sep 17 00:00:00 2001
From: Terrence Cole <terrence@mozilla.com>
Date: Tue, 17 Nov 2015 13:40:55 -0800
Subject: [PATCH] Bug 1225650 - Use stable hashing for JSObject2WrappedJSMap;
 r=jonco

---
 js/xpconnect/src/XPCMaps.cpp |  5 ++---
 js/xpconnect/src/XPCMaps.h   | 18 ++++--------------
 2 files changed, 6 insertions(+), 17 deletions(-)

diff --git a/js/xpconnect/src/XPCMaps.cpp b/js/xpconnect/src/XPCMaps.cpp
index 297e9776ce7..45876a9138d 100644
--- a/js/xpconnect/src/XPCMaps.cpp
+++ b/js/xpconnect/src/XPCMaps.cpp
@@ -119,12 +119,11 @@ JSObject2WrappedJSMap::UpdateWeakPointersAfterGC(XPCJSRuntime* runtime)
 
         // Remove or update the JSObject key in the table if necessary.
         JSObject* obj = e.front().key();
-        JSObject* prior = obj;
         JS_UpdateWeakPointerAfterGCUnbarriered(&obj);
         if (!obj)
             e.removeFront();
-        else if (obj != prior)
-            e.rekeyFront(obj);
+        else
+            e.front().mutableKey() = obj;
     }
 }
 
diff --git a/js/xpconnect/src/XPCMaps.h b/js/xpconnect/src/XPCMaps.h
index 15f10b6a360..7d585e93ea7 100644
--- a/js/xpconnect/src/XPCMaps.h
+++ b/js/xpconnect/src/XPCMaps.h
@@ -27,8 +27,10 @@
 
 class JSObject2WrappedJSMap
 {
-    typedef js::HashMap<JSObject*, nsXPCWrappedJS*, js::PointerHasher<JSObject*, 3>,
-                        js::SystemAllocPolicy> Map;
+    using Map = js::HashMap<JS::Heap<JSObject*>,
+                            nsXPCWrappedJS*,
+                            js::MovableCellHasher<JS::Heap<JSObject*>>,
+                            js::SystemAllocPolicy>;
 
 public:
     static JSObject2WrappedJSMap* newMap(int length) {
@@ -66,7 +68,6 @@ public:
             return p->value();
         if (!mTable.add(p, obj, wrapper))
             return nullptr;
-        JS_StoreObjectPostBarrierCallback(cx, KeyMarkCallback, obj, this);
         return wrapper;
     }
 
@@ -95,17 +96,6 @@ public:
 private:
     JSObject2WrappedJSMap() {}
 
-    /*
-     * This function is called during minor GCs for each key in the HashMap that
-     * has been moved.
-     */
-    static void KeyMarkCallback(JSTracer* trc, JSObject* key, void* data) {
-        JSObject2WrappedJSMap* self = static_cast<JSObject2WrappedJSMap*>(data);
-        JSObject* prior = key;
-        JS_CallUnbarrieredObjectTracer(trc, &key, "XPCJSRuntime::mWrappedJSMap key");
-        self->mTable.rekeyIfMoved(prior, key);
-    }
-
     Map mTable;
 };