--- a/widget/TextEvents.h
+++ b/widget/TextEvents.h
@@ -147,17 +147,16 @@ protected:
     , mAccessKeyForwardedToChild(false)
     , mUniqueId(0)
 #ifdef XP_MACOSX
     , mNativeModifierFlags(0)
     , mNativeKeyCode(0)
 #endif // #ifdef XP_MACOSX
     , mKeyNameIndex(KEY_NAME_INDEX_Unidentified)
     , mCodeNameIndex(CODE_NAME_INDEX_UNKNOWN)
-    , mInputMethodAppState(eNotHandled)
     , mIsRepeat(false)
     , mIsComposing(false)
     , mIsReserved(false)
     , mIsSynthesizedByTIP(false)
     , mEditCommandsForSingleLineEditorInitialized(false)
     , mEditCommandsForMultiLineEditorInitialized(false)
     , mEditCommandsForRichTextEditorInitialized(false)
   {
@@ -178,17 +177,16 @@ public:
     , mAccessKeyForwardedToChild(false)
     , mUniqueId(0)
 #ifdef XP_MACOSX
     , mNativeModifierFlags(0)
     , mNativeKeyCode(0)
 #endif // #ifdef XP_MACOSX
     , mKeyNameIndex(KEY_NAME_INDEX_Unidentified)
     , mCodeNameIndex(CODE_NAME_INDEX_UNKNOWN)
-    , mInputMethodAppState(eNotHandled)
     , mIsRepeat(false)
     , mIsComposing(false)
     , mIsReserved(false)
     , mIsSynthesizedByTIP(false)
     , mEditCommandsForSingleLineEditorInitialized(false)
     , mEditCommandsForMultiLineEditorInitialized(false)
     , mEditCommandsForRichTextEditorInitialized(false)
   {
@@ -285,25 +283,16 @@ public:
   uint32_t mNativeModifierFlags;
   uint16_t mNativeKeyCode;
 #endif // #ifdef XP_MACOSX
 
   // DOM KeyboardEvent.key
   KeyNameIndex mKeyNameIndex;
   // DOM KeyboardEvent.code
   CodeNameIndex mCodeNameIndex;
-  // Indicates that the event is being handled by input method app
-  typedef uint8_t InputMethodAppStateType;
-  enum InputMethodAppState : InputMethodAppStateType
-  {
-    eNotHandled, // not yet handled by intput method app
-    eHandling,   // being handled by intput method app
-    eHandled     // handled by input method app
-  };
-  InputMethodAppState mInputMethodAppState;
 
   // Indicates whether the event is generated by auto repeat or not.
   // if this is keyup event, always false.
   bool mIsRepeat;
   // Indicates whether the event is generated during IME (or deadkey)
   // composition.  This is initialized by EventStateManager.  So, key event
   // dispatchers don't need to initialize this.
   bool mIsComposing;
@@ -508,17 +497,16 @@ public:
 #ifdef XP_MACOSX
     mNativeKeyCode = aEvent.mNativeKeyCode;
     mNativeModifierFlags = aEvent.mNativeModifierFlags;
     mNativeCharacters.Assign(aEvent.mNativeCharacters);
     mNativeCharactersIgnoringModifiers.
       Assign(aEvent.mNativeCharactersIgnoringModifiers);
     mPluginTextEventString.Assign(aEvent.mPluginTextEventString);
 #endif
-    mInputMethodAppState = aEvent.mInputMethodAppState;
     mIsSynthesizedByTIP = aEvent.mIsSynthesizedByTIP;
 
     // Don't copy mEditCommandsFor*Editor because it may require a lot of
     // memory space.  For example, if the event is dispatched but grabbed by
     // a JS variable, they are not necessary anymore.
 
     mEditCommandsForSingleLineEditorInitialized =
       aEvent.mEditCommandsForSingleLineEditorInitialized;

--- a/widget/nsGUIEventIPC.h
+++ b/widget/nsGUIEventIPC.h
@@ -441,19 +441,16 @@ struct ParamTraits<mozilla::WidgetKeyboa
     WriteParam(aMsg, aParam.mPseudoCharCode);
     WriteParam(aMsg, aParam.mAlternativeCharCodes);
     WriteParam(aMsg, aParam.mIsRepeat);
     WriteParam(aMsg, aParam.mIsReserved);
     WriteParam(aMsg, aParam.mAccessKeyForwardedToChild);
     WriteParam(aMsg, aParam.mLocation);
     WriteParam(aMsg, aParam.mUniqueId);
     WriteParam(aMsg, aParam.mIsSynthesizedByTIP);
-    WriteParam(aMsg,
-               static_cast<paramType::InputMethodAppStateType>
-                 (aParam.mInputMethodAppState));
 #ifdef XP_MACOSX
     WriteParam(aMsg, aParam.mNativeKeyCode);
     WriteParam(aMsg, aParam.mNativeModifierFlags);
     WriteParam(aMsg, aParam.mNativeCharacters);
     WriteParam(aMsg, aParam.mNativeCharactersIgnoringModifiers);
     WriteParam(aMsg, aParam.mPluginTextEventString);
 #endif
 
@@ -467,34 +464,32 @@ struct ParamTraits<mozilla::WidgetKeyboa
     WriteParam(aMsg, aParam.mEditCommandsForMultiLineEditorInitialized);
     WriteParam(aMsg, aParam.mEditCommandsForRichTextEditorInitialized);
   }
 
   static bool Read(const Message* aMsg, PickleIterator* aIter, paramType* aResult)
   {
     mozilla::KeyNameIndexType keyNameIndex = 0;
     mozilla::CodeNameIndexType codeNameIndex = 0;
-    paramType::InputMethodAppStateType inputMethodAppState = 0;
     if (ReadParam(aMsg, aIter,
                   static_cast<mozilla::WidgetInputEvent*>(aResult)) &&
         ReadParam(aMsg, aIter, &keyNameIndex) &&
         ReadParam(aMsg, aIter, &codeNameIndex) &&
         ReadParam(aMsg, aIter, &aResult->mKeyValue) &&
         ReadParam(aMsg, aIter, &aResult->mCodeValue) &&
         ReadParam(aMsg, aIter, &aResult->mKeyCode) &&
         ReadParam(aMsg, aIter, &aResult->mCharCode) &&
         ReadParam(aMsg, aIter, &aResult->mPseudoCharCode) &&
         ReadParam(aMsg, aIter, &aResult->mAlternativeCharCodes) &&
         ReadParam(aMsg, aIter, &aResult->mIsRepeat) &&
         ReadParam(aMsg, aIter, &aResult->mIsReserved) &&
         ReadParam(aMsg, aIter, &aResult->mAccessKeyForwardedToChild) &&
         ReadParam(aMsg, aIter, &aResult->mLocation) &&
         ReadParam(aMsg, aIter, &aResult->mUniqueId) &&
         ReadParam(aMsg, aIter, &aResult->mIsSynthesizedByTIP) &&
-        ReadParam(aMsg, aIter, &inputMethodAppState) &&
 #ifdef XP_MACOSX
         ReadParam(aMsg, aIter, &aResult->mNativeKeyCode) &&
         ReadParam(aMsg, aIter, &aResult->mNativeModifierFlags) &&
         ReadParam(aMsg, aIter, &aResult->mNativeCharacters) &&
         ReadParam(aMsg, aIter, &aResult->mNativeCharactersIgnoringModifiers) &&
         ReadParam(aMsg, aIter, &aResult->mPluginTextEventString) &&
 #endif
         ReadParam(aMsg, aIter, &aResult->mEditCommandsForSingleLineEditor) &&
@@ -505,18 +500,16 @@ struct ParamTraits<mozilla::WidgetKeyboa
         ReadParam(aMsg, aIter,
                   &aResult->mEditCommandsForMultiLineEditorInitialized) &&
         ReadParam(aMsg, aIter,
                   &aResult->mEditCommandsForRichTextEditorInitialized)) {
       aResult->mKeyNameIndex = static_cast<mozilla::KeyNameIndex>(keyNameIndex);
       aResult->mCodeNameIndex =
         static_cast<mozilla::CodeNameIndex>(codeNameIndex);
       aResult->mNativeKeyEvent = nullptr;
-      aResult->mInputMethodAppState =
-        static_cast<paramType::InputMethodAppState>(inputMethodAppState);
       return true;
     }
     return false;
   }
 };
 
 template<>
 struct ParamTraits<mozilla::TextRangeStyle>