diff -r 000000000000 -r 6474c204b198 xpcom/ds/nsSupportsArray.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/ds/nsSupportsArray.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,129 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 nsSupportsArray_h__
+#define nsSupportsArray_h__
+
+//#define DEBUG_SUPPORTSARRAY 1
+
+#include "nsISupportsArray.h"
+#include "mozilla/Attributes.h"
+
+static const uint32_t kAutoArraySize = 8;
+
+class nsSupportsArray MOZ_FINAL : public nsISupportsArray {
+public:
+  nsSupportsArray(void);
+  ~nsSupportsArray(void); // nonvirtual since we're not subclassed
+
+  static nsresult
+  Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  NS_DECL_NSISERIALIZABLE
+
+  // nsICollection methods:
+  NS_IMETHOD Count(uint32_t *result) { *result = mCount; return NS_OK; }
+  NS_IMETHOD GetElementAt(uint32_t aIndex, nsISupports* *result);
+  NS_IMETHOD QueryElementAt(uint32_t aIndex, const nsIID & aIID, void * *aResult) {
+    if (aIndex < mCount) {
+      nsISupports* element = mArray[aIndex];
+      if (nullptr != element)
+        return element->QueryInterface(aIID, aResult);
+    }
+    return NS_ERROR_FAILURE;
+  }
+  NS_IMETHOD SetElementAt(uint32_t aIndex, nsISupports* value) {
+    return ReplaceElementAt(value, aIndex) ? NS_OK : NS_ERROR_FAILURE;
+  }
+  NS_IMETHOD AppendElement(nsISupports *aElement) {
+    // XXX Invalid cast of bool to nsresult (bug 778110)
+    return (nsresult)InsertElementAt(aElement, mCount)/* ? NS_OK : NS_ERROR_FAILURE*/;
+  }
+  // XXX this is badly named - should be RemoveFirstElement
+  NS_IMETHOD RemoveElement(nsISupports *aElement) {
+    // XXX Invalid cast of bool to nsresult (bug 778110)
+    return (nsresult)RemoveElement(aElement, 0)/* ? NS_OK : NS_ERROR_FAILURE*/;
+  }
+  NS_IMETHOD_(bool) MoveElement(int32_t aFrom, int32_t aTo);
+  NS_IMETHOD Enumerate(nsIEnumerator* *result);
+  NS_IMETHOD Clear(void);
+
+  // nsISupportsArray methods:
+  NS_IMETHOD_(bool) Equals(const nsISupportsArray* aOther);
+
+  NS_IMETHOD_(int32_t) IndexOf(const nsISupports* aPossibleElement);
+  NS_IMETHOD_(int32_t) IndexOfStartingAt(const nsISupports* aPossibleElement,
+                                         uint32_t aStartIndex = 0);
+  NS_IMETHOD_(int32_t) LastIndexOf(const nsISupports* aPossibleElement);
+
+  NS_IMETHOD GetIndexOf(nsISupports *aPossibleElement, int32_t *_retval) {
+    *_retval = IndexOf(aPossibleElement);
+    return NS_OK;
+  }
+  
+  NS_IMETHOD GetIndexOfStartingAt(nsISupports *aPossibleElement,
+                                  uint32_t aStartIndex, int32_t *_retval) {
+    *_retval = IndexOfStartingAt(aPossibleElement, aStartIndex);
+    return NS_OK;
+  }
+  
+  NS_IMETHOD GetLastIndexOf(nsISupports *aPossibleElement, int32_t *_retval) {
+    *_retval = LastIndexOf(aPossibleElement);
+    return NS_OK;
+  }
+  
+  NS_IMETHOD_(bool) InsertElementAt(nsISupports* aElement, uint32_t aIndex);
+
+  NS_IMETHOD_(bool) ReplaceElementAt(nsISupports* aElement, uint32_t aIndex);
+
+  NS_IMETHOD_(bool) RemoveElementAt(uint32_t aIndex) {
+    return RemoveElementsAt(aIndex,1);
+  }
+  NS_IMETHOD_(bool) RemoveElement(const nsISupports* aElement, uint32_t aStartIndex = 0);
+  NS_IMETHOD_(bool) RemoveLastElement(const nsISupports* aElement);
+
+  NS_IMETHOD DeleteLastElement(nsISupports *aElement) {
+    return (RemoveLastElement(aElement) ? NS_OK : NS_ERROR_FAILURE);
+  }
+  
+  NS_IMETHOD DeleteElementAt(uint32_t aIndex) {
+    return (RemoveElementAt(aIndex) ? NS_OK : NS_ERROR_FAILURE);
+  }
+  
+  NS_IMETHOD_(bool) AppendElements(nsISupportsArray* aElements) {
+    return InsertElementsAt(aElements,mCount);
+  }
+  
+  NS_IMETHOD Compact(void);
+
+  NS_IMETHOD Clone(nsISupportsArray **_retval);
+
+  NS_IMETHOD_(bool) InsertElementsAt(nsISupportsArray *aOther, uint32_t aIndex);
+
+  NS_IMETHOD_(bool) RemoveElementsAt(uint32_t aIndex, uint32_t aCount);
+
+  NS_IMETHOD_(bool) SizeTo(int32_t aSize);
+protected:
+  void DeleteArray(void);
+
+  NS_IMETHOD_(void) GrowArrayBy(int32_t aGrowBy);
+
+  nsISupports** mArray;
+  uint32_t mArraySize;
+  uint32_t mCount;
+  nsISupports*  mAutoArray[kAutoArraySize];
+#if DEBUG_SUPPORTSARRAY
+  uint32_t mMaxCount;
+  uint32_t mMaxSize;
+#endif
+
+private:
+  // Copy constructors are not allowed
+  nsSupportsArray(const nsISupportsArray& other);
+};
+
+#endif // nsSupportsArray_h__