diff -r 000000000000 -r 6474c204b198 intl/lwbrk/src/nsCarbonBreaker.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/intl/lwbrk/src/nsCarbonBreaker.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 2; 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/. */
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <stdint.h>
+#include "nsDebug.h"
+#include "nscore.h"
+
+void
+NS_GetComplexLineBreaks(const char16_t* aText, uint32_t aLength,
+                        uint8_t* aBreakBefore)
+{
+  NS_ASSERTION(aText, "aText shouldn't be null");
+
+  memset(aBreakBefore, 0, aLength * sizeof(uint8_t));
+
+  CFStringRef str = ::CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault, reinterpret_cast<const UniChar*>(aText), aLength, kCFAllocatorNull);
+  if (!str) {
+    return;
+  }
+
+  CFStringTokenizerRef st = ::CFStringTokenizerCreate(kCFAllocatorDefault, str,
+                                                      ::CFRangeMake(0, aLength),
+                                                      kCFStringTokenizerUnitLineBreak,
+                                                      nullptr);
+  if (!st) {
+    ::CFRelease(str);
+    return;
+  }
+
+  CFStringTokenizerTokenType tt = ::CFStringTokenizerAdvanceToNextToken(st);
+  while (tt != kCFStringTokenizerTokenNone) {
+    CFRange r = ::CFStringTokenizerGetCurrentTokenRange(st);
+    if (r.location != 0) { // Ignore leading edge
+      aBreakBefore[r.location] = true;
+    }
+    tt = CFStringTokenizerAdvanceToNextToken(st);
+  }
+
+  ::CFRelease(st);
+  ::CFRelease(str);
+}