diff --git a/mfbt/double-conversion/source/utils.h b/mfbt/double-conversion/source/utils.h
--- a/mfbt/double-conversion/source/utils.h
+++ b/mfbt/double-conversion/source/utils.h
@@ -26,38 +26,38 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef DOUBLE_CONVERSION_UTILS_H_
 #define DOUBLE_CONVERSION_UTILS_H_
 
 #include <stdlib.h>
 #include <string.h>
 
-#include <assert.h>
+#include "mozilla/Assertions.h"
 #ifndef ASSERT
 #define ASSERT(condition)         \
-    assert(condition);
+    MOZ_ASSERT(condition)
 #endif
 #ifndef UNIMPLEMENTED
-#define UNIMPLEMENTED() (abort())
+#define UNIMPLEMENTED() MOZ_CRASH()
 #endif
 #ifndef DOUBLE_CONVERSION_NO_RETURN
 #ifdef _MSC_VER
 #define DOUBLE_CONVERSION_NO_RETURN __declspec(noreturn)
 #else
 #define DOUBLE_CONVERSION_NO_RETURN __attribute__((noreturn))
 #endif
 #endif
 #ifndef UNREACHABLE
 #ifdef _MSC_VER
 void DOUBLE_CONVERSION_NO_RETURN abort_noreturn();
-inline void abort_noreturn() { abort(); }
+inline void abort_noreturn() { MOZ_CRASH(); }
 #define UNREACHABLE()   (abort_noreturn())
 #else
-#define UNREACHABLE()   (abort())
+#define UNREACHABLE()   MOZ_CRASH()
 #endif
 #endif
 
 
 // Double operations detection based on target architecture.
 // Linux uses a 80bit wide floating point stack on x86. This induces double
 // rounding, which in turn leads to wrong results.
 // An easy way to test if the floating-point operations are correct is to