Change SpellCheckProvider into a RenderFrameObserver

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1056 matching lines @@
 
   return frame()->editor().executeCommand(name, value);
 }
 
 bool WebLocalFrameImpl::isCommandEnabled(const WebString& name) const {
   DCHECK(frame());
   return frame()->editor().createCommand(name).isEnabled();
 }
 
 void WebLocalFrameImpl::enableSpellChecking(bool enable) {
+  CHECK(frame());

[Xiaocheng, 2017/04/07 01:43:46]

Crash site.

   if (enable == isSpellCheckingEnabled())
     return;
   frame()->spellChecker().toggleSpellCheckingEnabled();
 }
 
 bool WebLocalFrameImpl::isSpellCheckingEnabled() const {
   return frame()->spellChecker().isSpellCheckingEnabled();
 }
 
 void WebLocalFrameImpl::replaceMisspelledRange(const WebString& text) {
@@ skipping 1438 matching lines @@
 TextCheckerClient& WebLocalFrameImpl::textCheckerClient() const {
   return *m_textCheckerClient;
 }
 
 void WebLocalFrameImpl::setTextCheckClient(
     WebTextCheckClient* textCheckClient) {
   m_textCheckClient = textCheckClient;
 }
 
 }  // namespace blink