Media Galleries API Picasa: Add file watch to invalidate database data on disk write.

chrome/browser/media_galleries/fileapi/picasa/picasa_finder.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 "chrome/browser/media_galleries/fileapi/picasa/picasa_finder.h"
 
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "chrome/browser/storage_monitor/storage_info.h"
+#include "chrome/common/media_galleries/picasa_types.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace picasa {
 
 namespace {
 
 // Returns path of Picasa's DB3 database directory. May only be called on
 // threads that allow for disk IO, like the FILE thread or MediaTaskRunner.
 base::FilePath FindPicasaDatabaseOnFileThread() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
   base::FilePath path;
 
 #if defined(OS_WIN)
   // TODO(tommycli): Check registry for alternative path.
   if (!PathService::Get(base::DIR_LOCAL_APP_DATA, &path))
     return base::FilePath();
 #elif defined(OS_MACOSX)
   // TODO(tommycli): Check Mac Preferences for alternative path.
   if (!PathService::Get(base::DIR_APP_DATA, &path))
     return base::FilePath();
 #else
   return base::FilePath();
 #endif
 
-  path = path.AppendASCII("Google").AppendASCII("Picasa2").AppendASCII("db3");
+  path = path.AppendASCII("Google").AppendASCII("Picasa2")
+             .AppendASCII(kPicasaDatabaseDirName);
 
   // Verify actual existence
   if (!base::DirectoryExists(path))
     path.clear();
 
   return path;
 }
 
 void FinishOnOriginalThread(const PicasaFinder::DeviceIDCallback& callback,
                             const base::FilePath& database_path) {
   if (!database_path.empty())
     callback.Run(chrome::StorageInfo::MakeDeviceId(
         chrome::StorageInfo::PICASA,
         database_path.AsUTF8Unsafe()));
 }
 
-}
+}  // namespace
 
 void PicasaFinder::FindPicasaDatabase(
     const PicasaFinder::DeviceIDCallback& callback) {
   content::BrowserThread::PostTaskAndReplyWithResult(
       content::BrowserThread::FILE,
       FROM_HERE,
       base::Bind(&FindPicasaDatabaseOnFileThread),
       base::Bind(&FinishOnOriginalThread, callback));
 }
 
 }  // namespace picasa