new file mode 100644
--- /dev/null
+++ b/security/sandbox/chromium-shim/patches/with_update/mingw_fix_narrowing_conversion.patch
@@ -0,0 +1,57 @@
+# HG changeset patch
+# User Tom Ritter <tom@mozilla.com>
+# Date 1516719664 21600
+#      Tue Jan 23 09:01:04 2018 -0600
+# Node ID bac3e3b07a973f923ece3e1fed227a8122c29349
+# Parent  2f7b7b76bf330097dcf9369f6514c3855625931f
+Bug 1432381 Promote ints to unsigned ints, because they are assigned an unsigned int value 2148073472u r?bobowen
+
+diff --git a/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h b/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h
+--- a/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h
++++ b/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h
+@@ -122,19 +122,19 @@ struct SpecificOpcode {
+   int table_index_;
+ 
+   // The opcode type
+   InstructionType type_;
+ 
+   // Description of the type of the dest, src and aux operands,
+   // put together from an enOperandType flag and an enAddressingMethod
+   // flag.
+-  int flag_dest_;
+-  int flag_source_;
+-  int flag_aux_;
++  unsigned int flag_dest_;
++  unsigned int flag_source_;
++  unsigned int flag_aux_;
+ 
+   // We indicate the mnemonic for debugging purposes
+   const char* mnemonic_;
+ };
+ 
+ // The information we keep in our tables about each of the different
+ // valid instructions recognized by the IA-32 architecture.
+ struct Opcode {
+@@ -143,19 +143,19 @@ struct Opcode {
+   int table_index_;
+ 
+   // The opcode type
+   InstructionType type_;
+ 
+   // Description of the type of the dest, src and aux operands,
+   // put together from an enOperandType flag and an enAddressingMethod
+   // flag.
+-  int flag_dest_;
+-  int flag_source_;
+-  int flag_aux_;
++  unsigned int flag_dest_;
++  unsigned int flag_source_;
++  unsigned int flag_aux_;
+ 
+   // We indicate the mnemonic for debugging purposes
+   const char* mnemonic_;
+ 
+   // Alternative opcode info if certain prefixes are specified.
+   // In most cases, all of these are zeroed-out.  Only used if
+   // bPrefixDependent is true.
+   bool is_prefix_dependent_;

--- a/security/sandbox/chromium-shim/patches/with_update/patch_order.txt
+++ b/security/sandbox/chromium-shim/patches/with_update/patch_order.txt
@@ -11,9 +11,10 @@ revert_c++14_index_sequence_usage.patch
 fix_Wcomma_warning_in_time_cc.patch
 allow_read_only_all_paths_rule.patch
 revert_TargetNtSetInformationThread_change.patch
 mingw_base_win_get_caller.patch
 mingw_duplicate_instatinations.patch
 mingw_msvc_requirement_error.patch
 mingw_copy_s.patch
 mingw_operator_new.patch
-mingw_cast_getprocaddress.patch
\ No newline at end of file
+mingw_cast_getprocaddress.patch
+mingw_fix_narrowing_conversion.patch
\ No newline at end of file

--- a/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h
+++ b/security/sandbox/chromium/sandbox/win/src/sidestep/mini_disassembler_types.h
@@ -122,19 +122,19 @@ struct SpecificOpcode {
   int table_index_;
 
   // The opcode type
   InstructionType type_;
 
   // Description of the type of the dest, src and aux operands,
   // put together from an enOperandType flag and an enAddressingMethod
   // flag.
-  int flag_dest_;
-  int flag_source_;
-  int flag_aux_;
+  unsigned int flag_dest_;
+  unsigned int flag_source_;
+  unsigned int flag_aux_;
 
   // We indicate the mnemonic for debugging purposes
   const char* mnemonic_;
 };
 
 // The information we keep in our tables about each of the different
 // valid instructions recognized by the IA-32 architecture.
 struct Opcode {
@@ -143,19 +143,19 @@ struct Opcode {
   int table_index_;
 
   // The opcode type
   InstructionType type_;
 
   // Description of the type of the dest, src and aux operands,
   // put together from an enOperandType flag and an enAddressingMethod
   // flag.
-  int flag_dest_;
-  int flag_source_;
-  int flag_aux_;
+  unsigned int flag_dest_;
+  unsigned int flag_source_;
+  unsigned int flag_aux_;
 
   // We indicate the mnemonic for debugging purposes
   const char* mnemonic_;
 
   // Alternative opcode info if certain prefixes are specified.
   // In most cases, all of these are zeroed-out.  Only used if
   // bPrefixDependent is true.
   bool is_prefix_dependent_;