UserImageLoader: Remove DCHECK requiring success of ReadFileToString().

chrome/browser/chromeos/login/user_image_loader.cc

 // Copyright (c) 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/chromeos/login/user_image_loader.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 49 matching lines @@
       base::Bind(&UserImageLoader::DecodeImage,
                  this,
                  base::Passed(&data),
                  ImageInfo(std::string(), pixels_per_side, loaded_cb)));
 }
 
 void UserImageLoader::ReadAndDecodeImage(const ImageInfo& image_info) {
   DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
 
   scoped_ptr<std::string> data(new std::string);
-  const bool success =
-      base::ReadFileToString(base::FilePath(image_info.file_path), data.get());
-  DCHECK(success);
+  if (!base::ReadFileToString(base::FilePath(image_info.file_path), data.get()))
+    LOG(ERROR) << "Failed to read image " << image_info.file_path;
 
+  // In case ReadFileToString() fails, |data| is empty and DecodeImage() calls
+  // back to OnDecodeImageFailed().
   DecodeImage(data.Pass(), image_info);
 }
 
 void UserImageLoader::DecodeImage(const scoped_ptr<std::string> data,
                                   const ImageInfo& image_info) {
   DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
 
   scoped_refptr<ImageDecoder> image_decoder =
       new ImageDecoder(this, *data, image_codec_);
   image_info_map_.insert(std::make_pair(image_decoder.get(), image_info));
@@ skipping 58 matching lines @@
     return;
   }
   const LoadedCallback loaded_cb = it->second.loaded_cb;
   image_info_map_.erase(it);
 
   foreground_task_runner_->PostTask(FROM_HERE,
                                     base::Bind(loaded_cb, UserImage()));
 }
 
 }  // namespace chromeos