--- a/dom/events/VirtualKeyCodeList.h
+++ b/dom/events/VirtualKeyCodeList.h
@@ -7,221 +7,234 @@
 
 /**
  * This header file defines all DOM keys which are defined in nsIDOMKeyEvent.
  * You must define NS_DEFINE_VK macro before including this.
  *
  * It must have two arguments, (aDOMKeyName, aDOMKeyCode)
  * aDOMKeyName is a key name in DOM.
  * aDOMKeyCode is one of nsIDOMKeyEvent::DOM_VK_*.
+ *
+ * Optionally, you can define NS_DISALLOW_SAME_KEYCODE.
+ *
+ * If NS_DISALLOW_SAME_KEYCODE is defined, same keyCode won't listed up.
+ * This is useful when you create switch-case statement.
  */
 
 #define DEFINE_VK_INTERNAL(aKeyName) \
   NS_DEFINE_VK(VK##aKeyName, nsIDOMKeyEvent::DOM_VK##aKeyName)
 
 // Some keycode may have different name in nsIDOMKeyEvent from its key name.
 #define DEFINE_VK_INTERNAL2(aKeyName, aKeyCodeName) \
   NS_DEFINE_VK(VK##aKeyName, nsIDOMKeyEvent::DOM_VK##aKeyCodeName)
 
-DEFINE_VK_INTERNAL(_CANCEL),
-DEFINE_VK_INTERNAL(_HELP),
-DEFINE_VK_INTERNAL2(_BACK, _BACK_SPACE),
-DEFINE_VK_INTERNAL(_TAB),
-DEFINE_VK_INTERNAL(_CLEAR),
-DEFINE_VK_INTERNAL(_RETURN),
-DEFINE_VK_INTERNAL(_SHIFT),
-DEFINE_VK_INTERNAL(_CONTROL),
-DEFINE_VK_INTERNAL(_ALT),
-DEFINE_VK_INTERNAL(_PAUSE),
-DEFINE_VK_INTERNAL(_CAPS_LOCK),
-DEFINE_VK_INTERNAL(_KANA),
-DEFINE_VK_INTERNAL(_HANGUL),
-DEFINE_VK_INTERNAL(_EISU),
-DEFINE_VK_INTERNAL(_JUNJA),
-DEFINE_VK_INTERNAL(_FINAL),
-DEFINE_VK_INTERNAL(_HANJA),
-DEFINE_VK_INTERNAL(_KANJI),
-DEFINE_VK_INTERNAL(_ESCAPE),
-DEFINE_VK_INTERNAL(_CONVERT),
-DEFINE_VK_INTERNAL(_NONCONVERT),
-DEFINE_VK_INTERNAL(_ACCEPT),
-DEFINE_VK_INTERNAL(_MODECHANGE),
-DEFINE_VK_INTERNAL(_SPACE),
-DEFINE_VK_INTERNAL(_PAGE_UP),
-DEFINE_VK_INTERNAL(_PAGE_DOWN),
-DEFINE_VK_INTERNAL(_END),
-DEFINE_VK_INTERNAL(_HOME),
-DEFINE_VK_INTERNAL(_LEFT),
-DEFINE_VK_INTERNAL(_UP),
-DEFINE_VK_INTERNAL(_RIGHT),
-DEFINE_VK_INTERNAL(_DOWN),
-DEFINE_VK_INTERNAL(_SELECT),
-DEFINE_VK_INTERNAL(_PRINT),
-DEFINE_VK_INTERNAL(_EXECUTE),
-DEFINE_VK_INTERNAL(_PRINTSCREEN),
-DEFINE_VK_INTERNAL(_INSERT),
-DEFINE_VK_INTERNAL(_DELETE),
+DEFINE_VK_INTERNAL(_CANCEL)
+DEFINE_VK_INTERNAL(_HELP)
+DEFINE_VK_INTERNAL2(_BACK, _BACK_SPACE)
+DEFINE_VK_INTERNAL(_TAB)
+DEFINE_VK_INTERNAL(_CLEAR)
+DEFINE_VK_INTERNAL(_RETURN)
+DEFINE_VK_INTERNAL(_SHIFT)
+DEFINE_VK_INTERNAL(_CONTROL)
+DEFINE_VK_INTERNAL(_ALT)
+DEFINE_VK_INTERNAL(_PAUSE)
+DEFINE_VK_INTERNAL(_CAPS_LOCK)
+#ifdef NS_DISALLOW_SAME_KEYCODE
+DEFINE_VK_INTERNAL2(_KANA_OR_HANGUL, _KANA)
+#else // #ifdef NS_DISALLOW_SAME_KEYCODE
+DEFINE_VK_INTERNAL(_KANA)
+DEFINE_VK_INTERNAL(_HANGUL)
+#endif
+DEFINE_VK_INTERNAL(_EISU)
+DEFINE_VK_INTERNAL(_JUNJA)
+DEFINE_VK_INTERNAL(_FINAL)
+#ifdef NS_DISALLOW_SAME_KEYCODE
+DEFINE_VK_INTERNAL2(_HANJA_OR_KANJI, _HANJA)
+#else // #ifdef NS_DISALLOW_SAME_KEYCODE
+DEFINE_VK_INTERNAL(_HANJA)
+DEFINE_VK_INTERNAL(_KANJI)
+#endif
+DEFINE_VK_INTERNAL(_ESCAPE)
+DEFINE_VK_INTERNAL(_CONVERT)
+DEFINE_VK_INTERNAL(_NONCONVERT)
+DEFINE_VK_INTERNAL(_ACCEPT)
+DEFINE_VK_INTERNAL(_MODECHANGE)
+DEFINE_VK_INTERNAL(_SPACE)
+DEFINE_VK_INTERNAL(_PAGE_UP)
+DEFINE_VK_INTERNAL(_PAGE_DOWN)
+DEFINE_VK_INTERNAL(_END)
+DEFINE_VK_INTERNAL(_HOME)
+DEFINE_VK_INTERNAL(_LEFT)
+DEFINE_VK_INTERNAL(_UP)
+DEFINE_VK_INTERNAL(_RIGHT)
+DEFINE_VK_INTERNAL(_DOWN)
+DEFINE_VK_INTERNAL(_SELECT)
+DEFINE_VK_INTERNAL(_PRINT)
+DEFINE_VK_INTERNAL(_EXECUTE)
+DEFINE_VK_INTERNAL(_PRINTSCREEN)
+DEFINE_VK_INTERNAL(_INSERT)
+DEFINE_VK_INTERNAL(_DELETE)
 
-DEFINE_VK_INTERNAL(_0),
-DEFINE_VK_INTERNAL(_1),
-DEFINE_VK_INTERNAL(_2),
-DEFINE_VK_INTERNAL(_3),
-DEFINE_VK_INTERNAL(_4),
-DEFINE_VK_INTERNAL(_5),
-DEFINE_VK_INTERNAL(_6),
-DEFINE_VK_INTERNAL(_7),
-DEFINE_VK_INTERNAL(_8),
-DEFINE_VK_INTERNAL(_9),
+DEFINE_VK_INTERNAL(_0)
+DEFINE_VK_INTERNAL(_1)
+DEFINE_VK_INTERNAL(_2)
+DEFINE_VK_INTERNAL(_3)
+DEFINE_VK_INTERNAL(_4)
+DEFINE_VK_INTERNAL(_5)
+DEFINE_VK_INTERNAL(_6)
+DEFINE_VK_INTERNAL(_7)
+DEFINE_VK_INTERNAL(_8)
+DEFINE_VK_INTERNAL(_9)
 
-DEFINE_VK_INTERNAL(_COLON),
-DEFINE_VK_INTERNAL(_SEMICOLON),
-DEFINE_VK_INTERNAL(_LESS_THAN),
-DEFINE_VK_INTERNAL(_EQUALS),
-DEFINE_VK_INTERNAL(_GREATER_THAN),
-DEFINE_VK_INTERNAL(_QUESTION_MARK),
-DEFINE_VK_INTERNAL(_AT),
+DEFINE_VK_INTERNAL(_COLON)
+DEFINE_VK_INTERNAL(_SEMICOLON)
+DEFINE_VK_INTERNAL(_LESS_THAN)
+DEFINE_VK_INTERNAL(_EQUALS)
+DEFINE_VK_INTERNAL(_GREATER_THAN)
+DEFINE_VK_INTERNAL(_QUESTION_MARK)
+DEFINE_VK_INTERNAL(_AT)
 
-DEFINE_VK_INTERNAL(_A),
-DEFINE_VK_INTERNAL(_B),
-DEFINE_VK_INTERNAL(_C),
-DEFINE_VK_INTERNAL(_D),
-DEFINE_VK_INTERNAL(_E),
-DEFINE_VK_INTERNAL(_F),
-DEFINE_VK_INTERNAL(_G),
-DEFINE_VK_INTERNAL(_H),
-DEFINE_VK_INTERNAL(_I),
-DEFINE_VK_INTERNAL(_J),
-DEFINE_VK_INTERNAL(_K),
-DEFINE_VK_INTERNAL(_L),
-DEFINE_VK_INTERNAL(_M),
-DEFINE_VK_INTERNAL(_N),
-DEFINE_VK_INTERNAL(_O),
-DEFINE_VK_INTERNAL(_P),
-DEFINE_VK_INTERNAL(_Q),
-DEFINE_VK_INTERNAL(_R),
-DEFINE_VK_INTERNAL(_S),
-DEFINE_VK_INTERNAL(_T),
-DEFINE_VK_INTERNAL(_U),
-DEFINE_VK_INTERNAL(_V),
-DEFINE_VK_INTERNAL(_W),
-DEFINE_VK_INTERNAL(_X),
-DEFINE_VK_INTERNAL(_Y),
-DEFINE_VK_INTERNAL(_Z),
+DEFINE_VK_INTERNAL(_A)
+DEFINE_VK_INTERNAL(_B)
+DEFINE_VK_INTERNAL(_C)
+DEFINE_VK_INTERNAL(_D)
+DEFINE_VK_INTERNAL(_E)
+DEFINE_VK_INTERNAL(_F)
+DEFINE_VK_INTERNAL(_G)
+DEFINE_VK_INTERNAL(_H)
+DEFINE_VK_INTERNAL(_I)
+DEFINE_VK_INTERNAL(_J)
+DEFINE_VK_INTERNAL(_K)
+DEFINE_VK_INTERNAL(_L)
+DEFINE_VK_INTERNAL(_M)
+DEFINE_VK_INTERNAL(_N)
+DEFINE_VK_INTERNAL(_O)
+DEFINE_VK_INTERNAL(_P)
+DEFINE_VK_INTERNAL(_Q)
+DEFINE_VK_INTERNAL(_R)
+DEFINE_VK_INTERNAL(_S)
+DEFINE_VK_INTERNAL(_T)
+DEFINE_VK_INTERNAL(_U)
+DEFINE_VK_INTERNAL(_V)
+DEFINE_VK_INTERNAL(_W)
+DEFINE_VK_INTERNAL(_X)
+DEFINE_VK_INTERNAL(_Y)
+DEFINE_VK_INTERNAL(_Z)
 
-DEFINE_VK_INTERNAL(_WIN),
-DEFINE_VK_INTERNAL(_CONTEXT_MENU),
-DEFINE_VK_INTERNAL(_SLEEP),
+DEFINE_VK_INTERNAL(_WIN)
+DEFINE_VK_INTERNAL(_CONTEXT_MENU)
+DEFINE_VK_INTERNAL(_SLEEP)
 
-DEFINE_VK_INTERNAL(_NUMPAD0),
-DEFINE_VK_INTERNAL(_NUMPAD1),
-DEFINE_VK_INTERNAL(_NUMPAD2),
-DEFINE_VK_INTERNAL(_NUMPAD3),
-DEFINE_VK_INTERNAL(_NUMPAD4),
-DEFINE_VK_INTERNAL(_NUMPAD5),
-DEFINE_VK_INTERNAL(_NUMPAD6),
-DEFINE_VK_INTERNAL(_NUMPAD7),
-DEFINE_VK_INTERNAL(_NUMPAD8),
-DEFINE_VK_INTERNAL(_NUMPAD9),
-DEFINE_VK_INTERNAL(_MULTIPLY),
-DEFINE_VK_INTERNAL(_ADD),
-DEFINE_VK_INTERNAL(_SEPARATOR),
-DEFINE_VK_INTERNAL(_SUBTRACT),
-DEFINE_VK_INTERNAL(_DECIMAL),
-DEFINE_VK_INTERNAL(_DIVIDE),
+DEFINE_VK_INTERNAL(_NUMPAD0)
+DEFINE_VK_INTERNAL(_NUMPAD1)
+DEFINE_VK_INTERNAL(_NUMPAD2)
+DEFINE_VK_INTERNAL(_NUMPAD3)
+DEFINE_VK_INTERNAL(_NUMPAD4)
+DEFINE_VK_INTERNAL(_NUMPAD5)
+DEFINE_VK_INTERNAL(_NUMPAD6)
+DEFINE_VK_INTERNAL(_NUMPAD7)
+DEFINE_VK_INTERNAL(_NUMPAD8)
+DEFINE_VK_INTERNAL(_NUMPAD9)
+DEFINE_VK_INTERNAL(_MULTIPLY)
+DEFINE_VK_INTERNAL(_ADD)
+DEFINE_VK_INTERNAL(_SEPARATOR)
+DEFINE_VK_INTERNAL(_SUBTRACT)
+DEFINE_VK_INTERNAL(_DECIMAL)
+DEFINE_VK_INTERNAL(_DIVIDE)
 
-DEFINE_VK_INTERNAL(_F1),
-DEFINE_VK_INTERNAL(_F2),
-DEFINE_VK_INTERNAL(_F3),
-DEFINE_VK_INTERNAL(_F4),
-DEFINE_VK_INTERNAL(_F5),
-DEFINE_VK_INTERNAL(_F6),
-DEFINE_VK_INTERNAL(_F7),
-DEFINE_VK_INTERNAL(_F8),
-DEFINE_VK_INTERNAL(_F9),
-DEFINE_VK_INTERNAL(_F10),
-DEFINE_VK_INTERNAL(_F11),
-DEFINE_VK_INTERNAL(_F12),
-DEFINE_VK_INTERNAL(_F13),
-DEFINE_VK_INTERNAL(_F14),
-DEFINE_VK_INTERNAL(_F15),
-DEFINE_VK_INTERNAL(_F16),
-DEFINE_VK_INTERNAL(_F17),
-DEFINE_VK_INTERNAL(_F18),
-DEFINE_VK_INTERNAL(_F19),
-DEFINE_VK_INTERNAL(_F20),
-DEFINE_VK_INTERNAL(_F21),
-DEFINE_VK_INTERNAL(_F22),
-DEFINE_VK_INTERNAL(_F23),
-DEFINE_VK_INTERNAL(_F24),
+DEFINE_VK_INTERNAL(_F1)
+DEFINE_VK_INTERNAL(_F2)
+DEFINE_VK_INTERNAL(_F3)
+DEFINE_VK_INTERNAL(_F4)
+DEFINE_VK_INTERNAL(_F5)
+DEFINE_VK_INTERNAL(_F6)
+DEFINE_VK_INTERNAL(_F7)
+DEFINE_VK_INTERNAL(_F8)
+DEFINE_VK_INTERNAL(_F9)
+DEFINE_VK_INTERNAL(_F10)
+DEFINE_VK_INTERNAL(_F11)
+DEFINE_VK_INTERNAL(_F12)
+DEFINE_VK_INTERNAL(_F13)
+DEFINE_VK_INTERNAL(_F14)
+DEFINE_VK_INTERNAL(_F15)
+DEFINE_VK_INTERNAL(_F16)
+DEFINE_VK_INTERNAL(_F17)
+DEFINE_VK_INTERNAL(_F18)
+DEFINE_VK_INTERNAL(_F19)
+DEFINE_VK_INTERNAL(_F20)
+DEFINE_VK_INTERNAL(_F21)
+DEFINE_VK_INTERNAL(_F22)
+DEFINE_VK_INTERNAL(_F23)
+DEFINE_VK_INTERNAL(_F24)
 
-DEFINE_VK_INTERNAL(_NUM_LOCK),
-DEFINE_VK_INTERNAL(_SCROLL_LOCK),
+DEFINE_VK_INTERNAL(_NUM_LOCK)
+DEFINE_VK_INTERNAL(_SCROLL_LOCK)
 
-DEFINE_VK_INTERNAL(_WIN_OEM_FJ_JISHO),
-DEFINE_VK_INTERNAL(_WIN_OEM_FJ_MASSHOU),
-DEFINE_VK_INTERNAL(_WIN_OEM_FJ_TOUROKU),
-DEFINE_VK_INTERNAL(_WIN_OEM_FJ_LOYA),
-DEFINE_VK_INTERNAL(_WIN_OEM_FJ_ROYA),
+DEFINE_VK_INTERNAL(_WIN_OEM_FJ_JISHO)
+DEFINE_VK_INTERNAL(_WIN_OEM_FJ_MASSHOU)
+DEFINE_VK_INTERNAL(_WIN_OEM_FJ_TOUROKU)
+DEFINE_VK_INTERNAL(_WIN_OEM_FJ_LOYA)
+DEFINE_VK_INTERNAL(_WIN_OEM_FJ_ROYA)
 
-DEFINE_VK_INTERNAL(_CIRCUMFLEX),
-DEFINE_VK_INTERNAL(_EXCLAMATION),
-DEFINE_VK_INTERNAL(_DOUBLE_QUOTE),
-DEFINE_VK_INTERNAL(_HASH),
-DEFINE_VK_INTERNAL(_DOLLAR),
-DEFINE_VK_INTERNAL(_PERCENT),
-DEFINE_VK_INTERNAL(_AMPERSAND),
-DEFINE_VK_INTERNAL(_UNDERSCORE),
-DEFINE_VK_INTERNAL(_OPEN_PAREN),
-DEFINE_VK_INTERNAL(_CLOSE_PAREN),
-DEFINE_VK_INTERNAL(_ASTERISK),
-DEFINE_VK_INTERNAL(_PLUS),
-DEFINE_VK_INTERNAL(_PIPE),
-DEFINE_VK_INTERNAL(_HYPHEN_MINUS),
+DEFINE_VK_INTERNAL(_CIRCUMFLEX)
+DEFINE_VK_INTERNAL(_EXCLAMATION)
+DEFINE_VK_INTERNAL(_DOUBLE_QUOTE)
+DEFINE_VK_INTERNAL(_HASH)
+DEFINE_VK_INTERNAL(_DOLLAR)
+DEFINE_VK_INTERNAL(_PERCENT)
+DEFINE_VK_INTERNAL(_AMPERSAND)
+DEFINE_VK_INTERNAL(_UNDERSCORE)
+DEFINE_VK_INTERNAL(_OPEN_PAREN)
+DEFINE_VK_INTERNAL(_CLOSE_PAREN)
+DEFINE_VK_INTERNAL(_ASTERISK)
+DEFINE_VK_INTERNAL(_PLUS)
+DEFINE_VK_INTERNAL(_PIPE)
+DEFINE_VK_INTERNAL(_HYPHEN_MINUS)
 
-DEFINE_VK_INTERNAL(_OPEN_CURLY_BRACKET),
-DEFINE_VK_INTERNAL(_CLOSE_CURLY_BRACKET),
+DEFINE_VK_INTERNAL(_OPEN_CURLY_BRACKET)
+DEFINE_VK_INTERNAL(_CLOSE_CURLY_BRACKET)
 
-DEFINE_VK_INTERNAL(_TILDE),
+DEFINE_VK_INTERNAL(_TILDE)
 
-DEFINE_VK_INTERNAL(_VOLUME_MUTE),
-DEFINE_VK_INTERNAL(_VOLUME_DOWN),
-DEFINE_VK_INTERNAL(_VOLUME_UP),
+DEFINE_VK_INTERNAL(_VOLUME_MUTE)
+DEFINE_VK_INTERNAL(_VOLUME_DOWN)
+DEFINE_VK_INTERNAL(_VOLUME_UP)
 
-DEFINE_VK_INTERNAL(_COMMA),
-DEFINE_VK_INTERNAL(_PERIOD),
-DEFINE_VK_INTERNAL(_SLASH),
-DEFINE_VK_INTERNAL(_BACK_QUOTE),
-DEFINE_VK_INTERNAL(_OPEN_BRACKET),
-DEFINE_VK_INTERNAL(_BACK_SLASH),
-DEFINE_VK_INTERNAL(_CLOSE_BRACKET),
-DEFINE_VK_INTERNAL(_QUOTE),
+DEFINE_VK_INTERNAL(_COMMA)
+DEFINE_VK_INTERNAL(_PERIOD)
+DEFINE_VK_INTERNAL(_SLASH)
+DEFINE_VK_INTERNAL(_BACK_QUOTE)
+DEFINE_VK_INTERNAL(_OPEN_BRACKET)
+DEFINE_VK_INTERNAL(_BACK_SLASH)
+DEFINE_VK_INTERNAL(_CLOSE_BRACKET)
+DEFINE_VK_INTERNAL(_QUOTE)
 
-DEFINE_VK_INTERNAL(_META),
-DEFINE_VK_INTERNAL(_ALTGR),
+DEFINE_VK_INTERNAL(_META)
+DEFINE_VK_INTERNAL(_ALTGR)
 
-DEFINE_VK_INTERNAL(_WIN_ICO_HELP),
-DEFINE_VK_INTERNAL(_WIN_ICO_00),
-DEFINE_VK_INTERNAL(_WIN_ICO_CLEAR),
-DEFINE_VK_INTERNAL(_WIN_OEM_RESET),
-DEFINE_VK_INTERNAL(_WIN_OEM_JUMP),
-DEFINE_VK_INTERNAL(_WIN_OEM_PA1),
-DEFINE_VK_INTERNAL(_WIN_OEM_PA2),
-DEFINE_VK_INTERNAL(_WIN_OEM_PA3),
-DEFINE_VK_INTERNAL(_WIN_OEM_WSCTRL),
-DEFINE_VK_INTERNAL(_WIN_OEM_CUSEL),
-DEFINE_VK_INTERNAL(_WIN_OEM_ATTN),
-DEFINE_VK_INTERNAL(_WIN_OEM_FINISH),
-DEFINE_VK_INTERNAL(_WIN_OEM_COPY),
-DEFINE_VK_INTERNAL(_WIN_OEM_AUTO),
-DEFINE_VK_INTERNAL(_WIN_OEM_ENLW),
-DEFINE_VK_INTERNAL(_WIN_OEM_BACKTAB),
+DEFINE_VK_INTERNAL(_WIN_ICO_HELP)
+DEFINE_VK_INTERNAL(_WIN_ICO_00)
+DEFINE_VK_INTERNAL(_WIN_ICO_CLEAR)
+DEFINE_VK_INTERNAL(_WIN_OEM_RESET)
+DEFINE_VK_INTERNAL(_WIN_OEM_JUMP)
+DEFINE_VK_INTERNAL(_WIN_OEM_PA1)
+DEFINE_VK_INTERNAL(_WIN_OEM_PA2)
+DEFINE_VK_INTERNAL(_WIN_OEM_PA3)
+DEFINE_VK_INTERNAL(_WIN_OEM_WSCTRL)
+DEFINE_VK_INTERNAL(_WIN_OEM_CUSEL)
+DEFINE_VK_INTERNAL(_WIN_OEM_ATTN)
+DEFINE_VK_INTERNAL(_WIN_OEM_FINISH)
+DEFINE_VK_INTERNAL(_WIN_OEM_COPY)
+DEFINE_VK_INTERNAL(_WIN_OEM_AUTO)
+DEFINE_VK_INTERNAL(_WIN_OEM_ENLW)
+DEFINE_VK_INTERNAL(_WIN_OEM_BACKTAB)
 
-DEFINE_VK_INTERNAL(_ATTN),
-DEFINE_VK_INTERNAL(_CRSEL),
-DEFINE_VK_INTERNAL(_EXSEL),
-DEFINE_VK_INTERNAL(_EREOF),
-DEFINE_VK_INTERNAL(_PLAY),
-DEFINE_VK_INTERNAL(_ZOOM),
-DEFINE_VK_INTERNAL(_PA1),
+DEFINE_VK_INTERNAL(_ATTN)
+DEFINE_VK_INTERNAL(_CRSEL)
+DEFINE_VK_INTERNAL(_EXSEL)
+DEFINE_VK_INTERNAL(_EREOF)
+DEFINE_VK_INTERNAL(_PLAY)
+DEFINE_VK_INTERNAL(_ZOOM)
+DEFINE_VK_INTERNAL(_PA1)
 DEFINE_VK_INTERNAL(_WIN_OEM_CLEAR)
 
 #undef DEFINE_VK_INTERNAL
 #undef DEFINE_VK_INTERNAL2

--- a/dom/xbl/nsXBLPrototypeHandler.cpp
+++ b/dom/xbl/nsXBLPrototypeHandler.cpp
@@ -638,34 +638,38 @@ struct keyCodeData {
 };
 
 // All of these must be uppercase, since the function below does
 // case-insensitive comparison by converting to uppercase.
 // XXX: be sure to check this periodically for new symbol additions!
 static const keyCodeData gKeyCodes[] = {
 
 #define NS_DEFINE_VK(aDOMKeyName, aDOMKeyCode) \
-  { #aDOMKeyName, sizeof(#aDOMKeyName) - 1, aDOMKeyCode }
+  { #aDOMKeyName, sizeof(#aDOMKeyName) - 1, aDOMKeyCode },
 #include "mozilla/VirtualKeyCodeList.h"
 #undef NS_DEFINE_VK
+
+  { nullptr, 0, 0 }
 };
 
 int32_t nsXBLPrototypeHandler::GetMatchingKeyCode(const nsAString& aKeyName)
 {
   nsAutoCString keyName;
   keyName.AssignWithConversion(aKeyName);
   ToUpperCase(keyName); // We want case-insensitive comparison with data
                         // stored as uppercase.
 
   uint32_t keyNameLength = keyName.Length();
   const char* keyNameStr = keyName.get();
-  for (uint16_t i = 0; i < (sizeof(gKeyCodes) / sizeof(gKeyCodes[0])); ++i)
+  for (uint16_t i = 0; i < ArrayLength(gKeyCodes) - 1; ++i) {
     if (keyNameLength == gKeyCodes[i].strlength &&
-        !nsCRT::strcmp(gKeyCodes[i].str, keyNameStr))
+        !nsCRT::strcmp(gKeyCodes[i].str, keyNameStr)) {
       return gKeyCodes[i].keycode;
+    }
+  }
 
   return 0;
 }
 
 int32_t nsXBLPrototypeHandler::KeyToMask(int32_t key)
 {
   switch (key)
   {

--- a/widget/BasicEvents.h
+++ b/widget/BasicEvents.h
@@ -707,16 +707,86 @@ enum Modifier
 #define NS_DOM_KEYNAME_OS         "OS"
 
 /******************************************************************************
  * mozilla::Modifiers
  ******************************************************************************/
 
 typedef uint16_t Modifiers;
 
+class MOZ_STACK_CLASS GetModifiersName final : public nsAutoCString
+{
+public:
+  explicit GetModifiersName(Modifiers aModifiers)
+  {
+    if (aModifiers & MODIFIER_ALT) {
+      AssignLiteral(NS_DOM_KEYNAME_ALT);
+    }
+    if (aModifiers & MODIFIER_ALTGRAPH) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_ALTGRAPH);
+    }
+    if (aModifiers & MODIFIER_CAPSLOCK) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_CAPSLOCK);
+    }
+    if (aModifiers & MODIFIER_CONTROL) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_CONTROL);
+    }
+    if (aModifiers & MODIFIER_FN) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_FN);
+    }
+    if (aModifiers & MODIFIER_FNLOCK) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_FNLOCK);
+    }
+    if (aModifiers & MODIFIER_META) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_META);
+    }
+    if (aModifiers & MODIFIER_NUMLOCK) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_NUMLOCK);
+    }
+    if (aModifiers & MODIFIER_SCROLLLOCK) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_SCROLLLOCK);
+    }
+    if (aModifiers & MODIFIER_SHIFT) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_SHIFT);
+    }
+    if (aModifiers & MODIFIER_SYMBOL) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_SYMBOL);
+    }
+    if (aModifiers & MODIFIER_SYMBOLLOCK) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_SYMBOLLOCK);
+    }
+    if (aModifiers & MODIFIER_OS) {
+      MaybeAppendSeparator();
+      AppendLiteral(NS_DOM_KEYNAME_OS);
+    }
+    if (IsEmpty()) {
+      AssignLiteral("none");
+    }
+  }
+
+private:
+  void MaybeAppendSeparator()
+  {
+    if (!IsEmpty()) {
+      AppendLiteral(" | ");
+    }
+  }
+};
+
 /******************************************************************************
  * mozilla::WidgetInputEvent
  ******************************************************************************/
 
 class WidgetInputEvent : public WidgetGUIEvent
 {
 protected:
   WidgetInputEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget,

--- a/widget/EventForwards.h
+++ b/widget/EventForwards.h
@@ -5,16 +5,18 @@
 
 #ifndef mozilla_EventForwards_h__
 #define mozilla_EventForwards_h__
 
 #include <stdint.h>
 
 #include "nsTArray.h"
 
+class nsCString;
+
 /**
  * XXX Following enums should be in BasicEvents.h.  However, currently, it's
  *     impossible to use foward delearation for enum.
  */
 
 /**
  * Return status for event processors.
  */
@@ -89,30 +91,34 @@ enum KeyNameIndex : KeyNameIndexType
 #include "mozilla/KeyNameList.h"
   // If a DOM keyboard event is synthesized by script, this is used.  Then,
   // specified key name should be stored and use it as .key value.
   KEY_NAME_INDEX_USE_STRING
 };
 
 #undef NS_DEFINE_KEYNAME
 
+const nsCString ToString(KeyNameIndex aKeyNameIndex);
+
 #define NS_DEFINE_PHYSICAL_KEY_CODE_NAME(aCPPName, aDOMCodeName) \
   CODE_NAME_INDEX_##aCPPName,
 
 typedef uint8_t CodeNameIndexType;
 enum CodeNameIndex : CodeNameIndexType
 {
 #include "mozilla/PhysicalKeyCodeNameList.h"
   // If a DOM keyboard event is synthesized by script, this is used.  Then,
   // specified code name should be stored and use it as .code value.
   CODE_NAME_INDEX_USE_STRING
 };
 
 #undef NS_DEFINE_PHYSICAL_KEY_CODE_NAME
 
+const nsCString ToString(CodeNameIndex aCodeNameIndex);
+
 #define NS_DEFINE_COMMAND(aName, aCommandStr) , Command##aName
 
 typedef int8_t CommandInt;
 enum Command : CommandInt
 {
   CommandDoNothing
 
 #include "mozilla/CommandList.h"

--- a/widget/TextEvents.h
+++ b/widget/TextEvents.h
@@ -26,26 +26,27 @@
 
 class nsStringHashKey;
 template<class, class> class nsDataHashtable;
 
 /******************************************************************************
  * virtual keycode values
  ******************************************************************************/
 
-#define NS_DEFINE_VK(aDOMKeyName, aDOMKeyCode) NS_##aDOMKeyName = aDOMKeyCode
-
 enum
 {
+#define NS_DEFINE_VK(aDOMKeyName, aDOMKeyCode) NS_##aDOMKeyName = aDOMKeyCode,
 #include "mozilla/VirtualKeyCodeList.h"
+#undef NS_DEFINE_VK
+  NS_VK_UNKNOWN = 0xFF
 };
 
-#undef NS_DEFINE_VK
+namespace mozilla {
 
-namespace mozilla {
+const nsCString GetDOMKeyCodeName(uint32_t aKeyCode);
 
 namespace dom {
   class PBrowserParent;
   class PBrowserChild;
 } // namespace dom
 namespace plugins {
   class PPluginInstanceChild;
 } // namespace plugins

--- a/widget/WidgetEventImpl.cpp
+++ b/widget/WidgetEventImpl.cpp
@@ -7,16 +7,17 @@
 #include "mozilla/BasicEvents.h"
 #include "mozilla/ContentEvents.h"
 #include "mozilla/InternalMutationEvent.h"
 #include "mozilla/MiscEvents.h"
 #include "mozilla/MouseEvents.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/TextEvents.h"
 #include "mozilla/TouchEvents.h"
+#include "nsPrintfCString.h"
 
 namespace mozilla {
 
 /******************************************************************************
  * Global helper methods
  ******************************************************************************/
 
 const char*
@@ -53,16 +54,57 @@ ToChar(EventClassID aEventClassID)
 
 #undef NS_EVENT_CLASS
 #undef NS_ROOT_EVENT_CLASS
     default:
       return "illegal event class ID";
   }
 }
 
+const nsCString
+ToString(KeyNameIndex aKeyNameIndex)
+{
+  if (aKeyNameIndex == KEY_NAME_INDEX_USE_STRING) {
+    return NS_LITERAL_CSTRING("USE_STRING");
+  }
+  nsAutoString keyName;
+  WidgetKeyboardEvent::GetDOMKeyName(aKeyNameIndex, keyName);
+  return NS_ConvertUTF16toUTF8(keyName);
+}
+
+const nsCString
+ToString(CodeNameIndex aCodeNameIndex)
+{
+  if (aCodeNameIndex == CODE_NAME_INDEX_USE_STRING) {
+    return NS_LITERAL_CSTRING("USE_STRING");
+  }
+  nsAutoString codeName;
+  WidgetKeyboardEvent::GetDOMCodeName(aCodeNameIndex, codeName);
+  return NS_ConvertUTF16toUTF8(codeName);
+}
+
+const nsCString
+GetDOMKeyCodeName(uint32_t aKeyCode)
+{
+  switch (aKeyCode) {
+#define NS_DISALLOW_SAME_KEYCODE
+#define NS_DEFINE_VK(aDOMKeyName, aDOMKeyCode) \
+    case aDOMKeyCode: \
+      return NS_LITERAL_CSTRING(#aDOMKeyName);
+
+#include "mozilla/VirtualKeyCodeList.h"
+
+#undef NS_DEFINE_VK
+#undef NS_DISALLOW_SAME_KEYCODE
+
+    default:
+      return nsPrintfCString("Invalid DOM keyCode (0x%08X)", aKeyCode);
+  }
+}
+
 bool
 IsValidRawTextRangeValue(RawTextRangeType aRawTextRangeType)
 {
   switch (static_cast<TextRangeType>(aRawTextRangeType)) {
     case TextRangeType::eUninitialized:
     case TextRangeType::eCaret:
     case TextRangeType::eRawClause:
     case TextRangeType::eSelectedRawClause: