Data from the autocomplete predictor wasn't deleted immediately when deleting browsing history.

chrome/browser/predictors/autocomplete_action_predictor.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/browser/predictors/autocomplete_action_predictor.h"
 
 #include <math.h>
 #include <stddef.h>
 
 #include <vector>
@@ skipping 317 matching lines @@
   std::vector<AutocompleteActionPredictorTable::Row>* rows =
       new std::vector<AutocompleteActionPredictorTable::Row>();
   content::BrowserThread::PostTaskAndReply(
       content::BrowserThread::DB, FROM_HERE,
       base::Bind(&AutocompleteActionPredictorTable::GetAllRows, table_, rows),
       base::Bind(&AutocompleteActionPredictor::CreateCaches, AsWeakPtr(),
                  base::Owned(rows)));
 }
 
 void AutocompleteActionPredictor::DeleteAllRows() {
-  if (!initialized_)
-    return;
+  DCHECK(initialized_);
 
   db_cache_.clear();
   db_id_cache_.clear();
 
   if (table_.get()) {
     content::BrowserThread::PostTask(
         content::BrowserThread::DB, FROM_HERE,
         base::Bind(&AutocompleteActionPredictorTable::DeleteAllRows, table_));
   }
 
   UMA_HISTOGRAM_ENUMERATION("AutocompleteActionPredictor.DatabaseAction",
                             DATABASE_ACTION_DELETE_ALL, DATABASE_ACTION_COUNT);
 }
 
 void AutocompleteActionPredictor::DeleteRowsWithURLs(
     const history::URLRows& rows) {
-  if (!initialized_)
-    return;
+  DCHECK(initialized_);
 
   std::vector<AutocompleteActionPredictorTable::Row::Id> id_list;
 
   for (DBCacheMap::iterator it = db_cache_.begin(); it != db_cache_.end();) {
     if (std::find_if(rows.begin(), rows.end(),
                      history::URLRow::URLRowHasURL(it->first.url)) !=
         rows.end()) {
       const DBIdCacheMap::iterator id_it = db_id_cache_.find(it->first);
       DCHECK(id_it != db_id_cache_.end());
       id_list.push_back(id_it->second);
@@ skipping 67 matching lines @@
     const DBCacheKey key = { it->user_text, it->url };
     const DBCacheValue value = { it->number_of_hits, it->number_of_misses };
     db_cache_[key] = value;
     db_id_cache_[key] = it->id;
   }
 
   // If the history service is ready, delete any old or invalid entries.
   history::HistoryService* history_service =
       HistoryServiceFactory::GetForProfile(profile_,
                                            ServiceAccessType::EXPLICIT_ACCESS);
-  if (!TryDeleteOldEntries(history_service)) {
-    // Wait for the notification that the history service is ready and the URL
-    // DB is loaded.
-    if (history_service)
-      history_service_observer_.Add(history_service);
+  if (history_service) {
+    TryDeleteOldEntries(history_service);
+    history_service_observer_.Add(history_service);
   }
 }
 
-bool AutocompleteActionPredictor::TryDeleteOldEntries(
+void AutocompleteActionPredictor::TryDeleteOldEntries(
     history::HistoryService* service) {
   CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   DCHECK(!profile_->IsOffTheRecord());
   DCHECK(!initialized_);
 
   if (!service)
-    return false;
+    return;
 
   history::URLDatabase* url_db = service->InMemoryDatabase();
   if (!url_db)
-    return false;
+    return;
 
   DeleteOldEntries(url_db);
-  return true;
 }
 
 void AutocompleteActionPredictor::DeleteOldEntries(
     history::URLDatabase* url_db) {
   CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   DCHECK(!profile_->IsOffTheRecord());
   DCHECK(!initialized_);
   DCHECK(table_.get());
 
   std::vector<AutocompleteActionPredictorTable::Row::Id> ids_to_delete;
@@ skipping 84 matching lines @@
 void AutocompleteActionPredictor::Shutdown() {
   history_service_observer_.RemoveAll();
 }
 
 void AutocompleteActionPredictor::OnURLsDeleted(
     history::HistoryService* history_service,
     bool all_history,
     bool expired,
     const history::URLRows& deleted_rows,
     const std::set<GURL>& favicon_urls) {
-  if (!initialized_)
-    return;
+  DCHECK(initialized_);
 
   if (all_history)
     DeleteAllRows();
   else
     DeleteRowsWithURLs(deleted_rows);
 }
 
 void AutocompleteActionPredictor::OnHistoryServiceLoaded(
     history::HistoryService* history_service) {
-  TryDeleteOldEntries(history_service);
-  history_service_observer_.Remove(history_service);
+  if (!initialized_)
+    TryDeleteOldEntries(history_service);
 }
 
 AutocompleteActionPredictor::TransitionalMatch::TransitionalMatch() {
 }
 
 AutocompleteActionPredictor::TransitionalMatch::TransitionalMatch(
     const TransitionalMatch& other) = default;
 
 AutocompleteActionPredictor::TransitionalMatch::~TransitionalMatch() {
 }
 
 }  // namespace predictors