--- a/widget/windows/nsTextStore.cpp
+++ b/widget/windows/nsTextStore.cpp
@@ -1160,18 +1160,16 @@ bool nsTextStore::sDoNotReturnNoLayoutEr
   (NS_LITERAL_STRING("ATOK "))
 // NOTE: Free ChangJie 2010 missspells its name...
 #define TIP_NAME_FREE_CHANG_JIE_2010 \
   (NS_LITERAL_STRING("Free CangJie IME 10"))
 #define TIP_NAME_EASY_CHANGJEI \
   (NS_LITERAL_STRING( \
      "\x4E2D\x6587 (\x7E41\x9AD4) - \x6613\x9821\x8F38\x5165\x6CD5"))
 
-UINT nsTextStore::sFlushTIPInputMessage  = 0;
-
 #define TEXTSTORE_DEFAULT_VIEW (1)
 
 nsTextStore::nsTextStore()
   : mLockedContent(mComposition, mSelection)
   , mEditCookie(0)
   , mSinkMask(0)
   , mLock(0)
   , mLockQueued(0)
@@ -1268,28 +1266,16 @@ nsTextStore::Destroy(void)
   if (mComposition.IsComposing()) {
     NS_WARNING("Composition is still alive at destroying the text store");
     CommitCompositionInternal(false);
   }
 
   mLockedContent.Clear();
   mSelection.MarkDirty();
 
-  if (mWidget) {
-    // When blurred, Tablet Input Panel posts "blur" messages
-    // and try to insert text when the message is retrieved later.
-    // But by that time the text store is already destroyed,
-    // so try to get the message early
-    MSG msg;
-    if (WinUtils::PeekMessage(&msg, mWidget->GetWindowHandle(),
-                              sFlushTIPInputMessage, sFlushTIPInputMessage,
-                              PM_REMOVE)) {
-      ::DispatchMessageW(&msg);
-    }
-  }
   mContext = nullptr;
   if (mDocumentMgr) {
     mDocumentMgr->Pop(TF_POPF_ALL);
     mDocumentMgr = nullptr;
   }
   mSink = nullptr;
   mWidget = nullptr;
 
@@ -4617,19 +4603,16 @@ nsTextStore::Initialize()
     Preferences::GetBool("intl.tsf.hack.atok.create_native_caret", true);
   sDoNotReturnNoLayoutErrorToFreeChangJie =
     Preferences::GetBool(
       "intl.tsf.hack.free_chang_jie.do_not_return_no_layout_error", true);
   sDoNotReturnNoLayoutErrorToEasyChangjei =
     Preferences::GetBool(
       "intl.tsf.hack.easy_changjei.do_not_return_no_layout_error", true);
 
-  MOZ_ASSERT(!sFlushTIPInputMessage);
-  sFlushTIPInputMessage = ::RegisterWindowMessageW(L"Flush TIP Input Message");
-
   PR_LOG(sTextStoreLog, PR_LOG_ALWAYS,
     ("TSF:   nsTextStore::Initialize(), sTsfThreadMgr=0x%p, "
      "sTsfClientId=0x%08X, sEnabledTextStore=0x%p, sDisplayAttrMgr=0x%p, "
      "sCategoryMgr=0x%p, sTsfDisabledDocumentMgr=0x%p, sTsfDisabledContext=%p, "
      "sCreateNativeCaretForATOK=%s, "
      "sDoNotReturnNoLayoutErrorToFreeChangJie=%s, "
      "sDoNotReturnNoLayoutErrorToEasyChangjei=%s",
      sTsfThreadMgr, sTsfClientId, sEnabledTextStore, sDisplayAttrMgr,

--- a/widget/windows/nsTextStore.h
+++ b/widget/windows/nsTextStore.h
@@ -757,15 +757,11 @@ protected:
   static ITfContext* sTsfDisabledContext;
 
   static ITfInputProcessorProfiles* sInputProcessorProfiles;
 
   // Enables/Disables hack for specific TIP.
   static bool sCreateNativeCaretForATOK;
   static bool sDoNotReturnNoLayoutErrorToFreeChangJie;
   static bool sDoNotReturnNoLayoutErrorToEasyChangjei;
-
-  // Message the Tablet Input Panel uses to flush text during blurring.
-  // See comments in Destroy
-  static UINT           sFlushTIPInputMessage;
 };
 
 #endif /*NSTEXTSTORE_H_*/