Make WebSpellCheckClient aware of leak detection

chrome/renderer/spellchecker/spellcheck_provider.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/spellchecker/spellcheck_provider.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/renderer/spellchecker/spellcheck.h"
@@ skipping 157 matching lines @@
     WebTextCheckingCompletion* completion) {
   std::vector<SpellCheckMarker> spellcheck_markers;
   for (size_t i = 0; i < markers.size(); ++i) {
     spellcheck_markers.push_back(
         SpellCheckMarker(markers[i], marker_offsets[i]));
   }
   RequestTextChecking(text, completion, spellcheck_markers);
   UMA_HISTOGRAM_COUNTS("SpellCheck.api.async", text.length());
 }
 
+void SpellCheckProvider::prepareForLeakDetection() {

[please use gerrit instead, 2016/08/09 16:47:57]

Let's use a name that better describes what happens in this function. For
example, "cancelCheckingAllText". What do you think?

[Xiaocheng, 2016/08/10 01:14:47]

Renamed to "cancelAllPendingRequests", which sounds better to me.

+  for (WebTextCheckCompletions::iterator iter(&text_check_completions_);
+       !iter.IsAtEnd(); iter.Advance())
+    iter.GetCurrentValue()->didCancelCheckingText();
+  text_check_completions_.Clear();
+}
+
 void SpellCheckProvider::showSpellingUI(bool show) {
 #if defined(USE_BROWSER_SPELLCHECKER)
   UMA_HISTOGRAM_BOOLEAN("SpellCheck.api.showUI", show);
   Send(new SpellCheckHostMsg_ShowSpellingPanel(routing_id(), show));
 #endif
 }
 
 bool SpellCheckProvider::isShowingSpellingUI() {
   return spelling_panel_visible_;
 }
@@ skipping 163 matching lines @@
       return true;
     }
   }
 
   return false;
 }
 
 void SpellCheckProvider::OnDestruct() {
   delete this;
 }