Revert 171023 - Reverting r171011, this rev was a fix for that

chrome/browser/chromeos/extensions/wallpaper_private_api.cc

 // Copyright (c) 2012 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/chromeos/extensions/wallpaper_private_api.h"
 
 #include <vector>
 
 #include "ash/shell.h"
 #include "ash/wm/window_cycle_controller.h"
@@ skipping 72 matching lines @@
 bool GetData(int key, const std::string& file_name, std::string* data) {
   FilePath data_dir;
   CHECK(PathService::Get(key, &data_dir));
   if (!file_util::DirectoryExists(data_dir) &&
       !file_util::CreateDirectory(data_dir))
     return false;
 
   FilePath file_path = data_dir.Append(file_name);
 
   return !file_util::PathExists(file_path) ||
-         !file_util::ReadFileToString(file_path, data);
+         (file_util::ReadFileToString(file_path, data) != -1);
 }
 
 class WindowStateManager;
 
 // static
 WindowStateManager* g_window_state_manager = NULL;
 
 // WindowStateManager remembers which windows have been minimized in order to
 // restore them when the wallpaper viewer is hidden.
 class WindowStateManager : public aura::WindowObserver {
@@ skipping 456 matching lines @@
     BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&WallpaperSaveThumbnailFunction::Success, this));
   } else {
     BrowserThread::PostTask(
           BrowserThread::UI, FROM_HERE,
           base::Bind(&WallpaperSaveThumbnailFunction::Failure,
                      this, file_name));
   }
 }