Move InMemoryURLIndex Caching Operations to FILE Thread

chrome/browser/history/history_backend.cc

Index: chrome/browser/history/history_backend.cc
===================================================================
--- chrome/browser/history/history_backend.cc	(revision 117518)
+++ chrome/browser/history/history_backend.cc	(working copy)
@@ -27,8 +27,10 @@
 #include "chrome/browser/history/in_memory_history_backend.h"
 #include "chrome/browser/history/page_usage_data.h"
 #include "chrome/browser/history/top_sites.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/download/download_persistent_store_info.h"
 #include "googleurl/src/gurl.h"
@@ -200,7 +202,8 @@
 
 // HistoryBackend --------------------------------------------------------------
 
-HistoryBackend::HistoryBackend(const FilePath& history_dir,
+HistoryBackend::HistoryBackend(Profile* profile,
+                               const FilePath& history_dir,
                                int id,
                                Delegate* delegate,
                                BookmarkService* bookmark_service)
@@ -212,6 +215,9 @@
       backend_destroy_message_loop_(NULL),
       segment_queried_(false),
       bookmark_service_(bookmark_service) {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableHistoryQuickProvider))
+    in_memory_url_index_ = new InMemoryURLIndex(profile, history_dir_);
 }
 
 HistoryBackend::~HistoryBackend() {
@@ -649,6 +655,9 @@
     archived_db_.reset();
   }
 
+  if (in_memory_url_index_.get())
+    in_memory_url_index_->Init(languages);
+
   // Tell the expiration module about all the nice databases we made. This must
   // happen before db_->Init() is called since the callback ForceArchiveHistory
   // may need to expire stuff.