Fix "unreachable code" warnings (MSVC warning 4702) in content/.

content/browser/dom_storage/dom_storage_database.cc

 // Copyright 2013 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 "content/browser/dom_storage/dom_storage_database.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "sql/statement.h"
@@ skipping 211 matching lines @@
     return INVALID;
 
   switch (statement.DeclaredColumnType(1)) {
     case sql::COLUMN_TYPE_BLOB:
       return V2;
     case sql::COLUMN_TYPE_TEXT:
       return V1;
     default:
       return INVALID;
   }
-  NOTREACHED();
-  return INVALID;
 }
 
 bool DOMStorageDatabase::CreateTableV2() {
   DCHECK(IsOpen());
 
   return db_->Execute(
       "CREATE TABLE ItemTable ("
       "key TEXT UNIQUE ON CONFLICT REPLACE, "
       "value BLOB NOT NULL ON CONFLICT FAIL)");
 }
@@ skipping 42 matching lines @@
       CreateTableV2() &&
       CommitChanges(false, values) &&
       migration.Commit();
 }
 
 void DOMStorageDatabase::Close() {
   db_.reset(NULL);
 }
 
 }  // namespace content