[SQLite] Hack to touch page cache to debug slow connection close.

sql/connection.cc

 // Copyright (c) 2011 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 "sql/connection.h"
 
 #include <string.h>
 
 #include "base/file_path.h"
 #include "base/logging.h"
@@ skipping 93 matching lines @@
 }
 
 bool Connection::OpenInMemory() {
   return OpenInternal(":memory:");
 }
 
 void Connection::Close() {
   statement_cache_.clear();
   DCHECK(open_statements_.empty());
   if (db_) {
+    // TODO(shess): Some additional code to debug http://crbug.com/95527 .
+    // If you are reading this due to link errors or something, it can
+    // be safely removed.
+#if defined(HAS_SQLITE3_95527)
+    unsigned int nTouched = 0;
+    sqlite3_95527(db_, &nTouched);
+
+    // If a VERY large amount of memory was touched, crash.  This
+    // should never happen.
+    // TODO(shess): Pull this in.  It should be page_size * page_cache
+    // or something like that, 4M or 16M.  For now it's just to
+    // prevent optimization.
+    CHECK_LT(nTouched, 1000*1000*1000U);
+#endif
     sqlite3_close(db_);
     db_ = NULL;
   }
 }
 
 void Connection::Preload() {
   if (!db_) {
     NOTREACHED();
     return;
   }
@@ skipping 293 matching lines @@
 
 int Connection::OnSqliteError(int err, sql::Statement *stmt) {
   if (error_delegate_.get())
     return error_delegate_->OnError(err, this, stmt);
   // The default handling is to assert on debug and to ignore on release.
   NOTREACHED() << GetErrorMessage();
   return err;
 }
 
 }  // namespace sql