Fix: Spurious SQL error message is logged in priming SQLite database cache.

This patch depends on the MetaTableHelper refactoring in:
http://codereview.chromium.org/150094

Currently, a spurious SQL error message is logged every time a unit test that
access SQLite database runs.

Example:
[----------] 6 tests from HistoryBackendTest
[ RUN      ] HistoryBackendTest.Loaded
[5660:5304:0630/150705:414864129:ERROR:sqlite_utils.cc(204)] SQLStatement.prepare_v2 failed: no such table: meta

BUG=none
TEST=n/a

Review URL: http://codereview.chromium.org/150095

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19803 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 2 insertions, 21 deletions

diff --git a/chrome/browser/history/history_database.cc b/chrome/browser/history/history_database.cc
index db63a34..7b198fc 100644
--- a/chrome/browser/history/history_database.cc
+++ b/chrome/browser/history/history_database.cc
@@ -57,8 +57,8 @@ InitStatus HistoryDatabase::Init(const FilePath& history_name,
   // Make sure the statement cache is properly initialized.
   statement_cache_->set_db(db_);
 
-  // Prime the cache. See the header file's documentation for this function.
-  PrimeCache();
+  // Prime the cache.
+  MetaTableHelper::PrimeCache(std::string(), db_);
 
   // Create the tables and indices.
   // NOTE: If you add something here, also add it to
@@ -88,19 +88,6 @@ void HistoryDatabase::BeginExclusiveMode() {
   sqlite3_exec(db_, "PRAGMA locking_mode=EXCLUSIVE", NULL, NULL, NULL);
 }
 
-void HistoryDatabase::PrimeCache() {
-  // A statement must be open for the preload command to work. If the meta
-  // table can't be read, it probably means this is a new database and there
-  // is nothing to preload (so it's OK we do nothing).
-  SQLStatement dummy;
-  if (dummy.prepare(db_, "SELECT * from meta") != SQLITE_OK)
-    return;
-  if (dummy.step() != SQLITE_ROW)
-    return;
-
-  sqlite3Preload(db_);
-}
-
 // static
 int HistoryDatabase::GetCurrentVersion() {
   return kCurrentVersionNumber;
diff --git a/chrome/browser/history/history_database.h b/chrome/browser/history/history_database.h
index 5791c07..61a27d7 100644
--- a/chrome/browser/history/history_database.h
+++ b/chrome/browser/history/history_database.h
@@ -129,12 +129,6 @@ class HistoryDatabase : public DownloadDatabase,
   virtual sqlite3* GetDB();
   virtual SqliteStatementCache& GetStatementCache();
 
-  // Primes the sqlite cache on startup by filling it with the file in sequence
-  // until there is no more data or the cache is full. Since this is one
-  // contiguous read operation, it is much faster than letting the pages come
-  // in on-demand (which causes lots of seeks).
-  void PrimeCache();
-
   // Migration -----------------------------------------------------------------
 
   // Makes sure the version is up-to-date, updating if necessary. If the