diff --git a/dom/base/TextInputProcessor.cpp b/dom/base/TextInputProcessor.cpp
index e6506839b7ce..4fc6f9f4171a 100644
--- a/dom/base/TextInputProcessor.cpp
+++ b/dom/base/TextInputProcessor.cpp
@@ -766,6 +766,8 @@ TextInputProcessor::PrepareKeyboardEventToDispatch(
         aKeyboardEvent.mKeyNameIndex);
   }
 
+  aKeyboardEvent.mIsSynthesizedByTIP = (mForTests)? false : true;
+
   return NS_OK;
 }
 
diff --git a/widget/TextEvents.h b/widget/TextEvents.h
index 69f47772bafd..dc803004c151 100644
--- a/widget/TextEvents.h
+++ b/widget/TextEvents.h
@@ -117,6 +117,8 @@ protected:
     , mNativeKeyCode(0)
     , mNativeModifierFlags(0)
 #endif
+    , mInputMethodAppState(eNotHandled)
+    , mIsSynthesizedByTIP(false)
   {
   }
 
@@ -142,6 +144,8 @@ public:
     , mNativeKeyCode(0)
     , mNativeModifierFlags(0)
 #endif
+    , mInputMethodAppState(eNotHandled)
+    , mIsSynthesizedByTIP(false)
   {
   }
 
@@ -211,6 +215,20 @@ public:
   nsString mPluginTextEventString;
 #endif
 
+  // 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 synthesized from Text Input Processor
+  // or an actual event from nsAppShell.
+  bool mIsSynthesizedByTIP;
+
   // If the key should cause keypress events, this returns true.
   // Otherwise, false.
   bool ShouldCauseKeypressEvents() const;
@@ -338,6 +356,8 @@ public:
       Assign(aEvent.mNativeCharactersIgnoringModifiers);
     mPluginTextEventString.Assign(aEvent.mPluginTextEventString);
 #endif
+    mInputMethodAppState = aEvent.mInputMethodAppState;
+    mIsSynthesizedByTIP = aEvent.mIsSynthesizedByTIP;
   }
 
 private:
diff --git a/widget/nsGUIEventIPC.h b/widget/nsGUIEventIPC.h
index 8b1c2edec9ff..7aa124754caa 100644
--- a/widget/nsGUIEventIPC.h
+++ b/widget/nsGUIEventIPC.h
@@ -384,6 +384,10 @@ struct ParamTraits<mozilla::WidgetKeyboardEvent>
     WriteParam(aMsg, aParam.mIsRepeat);
     WriteParam(aMsg, aParam.location);
     WriteParam(aMsg, aParam.mUniqueId);
+    WriteParam(aMsg, aParam.mIsSynthesizedByTIP);
+    WriteParam(aMsg,
+               static_cast<mozilla::WidgetKeyboardEvent::InputMethodAppStateType>
+                 (aParam.mInputMethodAppState));
 #ifdef XP_MACOSX
     WriteParam(aMsg, aParam.mNativeKeyCode);
     WriteParam(aMsg, aParam.mNativeModifierFlags);
@@ -398,6 +402,8 @@ struct ParamTraits<mozilla::WidgetKeyboardEvent>
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
   {
     uint32_t keyNameIndex = 0, codeNameIndex = 0;
+    mozilla::WidgetKeyboardEvent::InputMethodAppStateType
+      inputMethodAppState = 0;
     if (ReadParam(aMsg, aIter,
                   static_cast<mozilla::WidgetInputEvent*>(aResult)) &&
         ReadParam(aMsg, aIter, &keyNameIndex) &&
@@ -411,7 +417,9 @@ struct ParamTraits<mozilla::WidgetKeyboardEvent>
         ReadParam(aMsg, aIter, &aResult->isChar) &&
         ReadParam(aMsg, aIter, &aResult->mIsRepeat) &&
         ReadParam(aMsg, aIter, &aResult->location) &&
-        ReadParam(aMsg, aIter, &aResult->mUniqueId)
+        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)
@@ -425,6 +433,9 @@ struct ParamTraits<mozilla::WidgetKeyboardEvent>
       aResult->mCodeNameIndex =
         static_cast<mozilla::CodeNameIndex>(codeNameIndex);
       aResult->mNativeKeyEvent = nullptr;
+      aResult->mInputMethodAppState =
+        static_cast<mozilla::WidgetKeyboardEvent::InputMethodAppState>
+          (inputMethodAppState);
       return true;
     }
     return false;
@@ -975,4 +986,3 @@ struct ParamTraits<mozilla::widget::CandidateWindowPosition>
 } // namespace IPC
 
 #endif // nsGUIEventIPC_h__
-