Introduce Range::dispose() for prompt detachment from owner Document.

Source/core/editing/spellcheck/SpellCheckRequester.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 193 matching lines @@
         m_processingRequest->didCancel();
 }
 
 void SpellCheckRequester::invokeRequest(PassRefPtrWillBeRawPtr<SpellCheckRequest> request)
 {
     ASSERT(!m_processingRequest);
     m_processingRequest = request;
     client().requestCheckingOfString(m_processingRequest);
 }
 
+void SpellCheckRequester::clearProcessingRequest()
+{
+    // This assumes that m_processingRequest's Ranges aren't shared.
+    if (m_processingRequest->checkingRange())
+        m_processingRequest->checkingRange()->dispose();
+    if (m_processingRequest->paragraphRange())
+        m_processingRequest->paragraphRange()->dispose();
+
+    m_processingRequest.clear();
+}
+
 void SpellCheckRequester::enqueueRequest(PassRefPtrWillBeRawPtr<SpellCheckRequest> request)
 {
     ASSERT(request);
     bool continuation = false;
     if (!m_requestQueue.isEmpty()) {
         RefPtrWillBeRawPtr<SpellCheckRequest> lastRequest = m_requestQueue.last();
         // It's a continuation if the number of the last request got incremented in the new one and
         // both apply to the same editable.
         continuation = request->rootEditableElement() == lastRequest->rootEditableElement()
             && request->requestNumber() == lastRequest->requestNumber() + 1;
@@ skipping 20 matching lines @@
     if (m_processingRequest->data().sequence() != sequence) {
         m_requestQueue.clear();
         return;
     }
 
     frame().spellChecker().markAndReplaceFor(m_processingRequest, results);
 
     if (m_lastProcessedSequence < sequence)
         m_lastProcessedSequence = sequence;
 
-    m_processingRequest.clear();
+    clearProcessingRequest();
     if (!m_requestQueue.isEmpty())
         m_timerToProcessQueuedRequest.startOneShot(0, FROM_HERE);
 }
 
 void SpellCheckRequester::didCheckSucceed(int sequence, const Vector<TextCheckingResult>& results)
 {
     TextCheckingRequestData requestData = m_processingRequest->data();
     if (requestData.sequence() == sequence) {
         DocumentMarker::MarkerTypes markers = DocumentMarker::SpellCheckClientMarkers();
         if (!requestData.maskContains(TextCheckingTypeSpelling))
@@ skipping 13 matching lines @@
 }
 
 DEFINE_TRACE(SpellCheckRequester)
 {
     visitor->trace(m_frame);
     visitor->trace(m_processingRequest);
     visitor->trace(m_requestQueue);
 }
 
 } // namespace blink