Revert of Move file_handlers API from //chrome to //extensions

chrome/browser/extensions/api/file_handlers/directory_util.cc

+// Copyright 2016 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/extensions/api/file_handlers/directory_util.h"
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/base/filename_util.h"
+#include "storage/browser/fileapi/file_system_url.h"
+
+#if defined(OS_CHROMEOS)
+#include "extensions/browser/api/extensions_api_client.h"
+#include "extensions/browser/api/file_handlers/non_native_file_system_delegate.h"
+#endif
+
+namespace extensions {
+namespace app_file_handler_util {
+
+namespace {
+
+void GetIsDirectoryFromFileInfo(const base::FilePath& path,
+                                bool* is_directory) {
+  base::File::Info file_info;
+  *is_directory = GetFileInfo(path, &file_info) && file_info.is_directory;
+}
+
+void OnGetIsDirectoryFromFileInfoCompleted(
+    std::unique_ptr<bool> is_directory,
+    const base::Callback<void(bool)>& callback) {
+  callback.Run(*is_directory);
+}
+
+// The callback parameter contains the result and is required to support
+// both native local directories to avoid UI thread and non native local
+// path directories for the IsNonNativeLocalPathDirectory API.
+void EntryIsDirectory(Profile* profile,
+                      const base::FilePath& path,
+                      const base::Callback<void(bool)>& callback) {
+#if defined(OS_CHROMEOS)
+  NonNativeFileSystemDelegate* delegate =
+      ExtensionsAPIClient::Get()->GetNonNativeFileSystemDelegate();
+  if (delegate && delegate->IsUnderNonNativeLocalPath(profile, path)) {
+    delegate->IsNonNativeLocalPathDirectory(profile, path, callback);
+    return;
+  }
+#endif
+
+  std::unique_ptr<bool> is_directory(new bool);
+  bool* const is_directory_ptr = is_directory.get();
+
+  content::BrowserThread::PostBlockingPoolTaskAndReply(
+      FROM_HERE,
+      base::Bind(&GetIsDirectoryFromFileInfo, path, is_directory_ptr),
+      base::Bind(&OnGetIsDirectoryFromFileInfoCompleted,
+                 base::Passed(&is_directory), callback));
+}
+
+}  // namespace
+
+IsDirectoryCollector::IsDirectoryCollector(Profile* profile)
+    : profile_(profile), left_(0), weak_ptr_factory_(this) {}
+
+IsDirectoryCollector::~IsDirectoryCollector() {}
+
+void IsDirectoryCollector::CollectForEntriesPaths(
+    const std::vector<base::FilePath>& paths,
+    const CompletionCallback& callback) {
+  DCHECK(!callback.is_null());
+  paths_ = paths;
+  callback_ = callback;
+
+  DCHECK(!result_.get());
+  result_.reset(new std::set<base::FilePath>());
+  left_ = paths.size();
+
+  if (!left_) {
+    // Nothing to process.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback_, base::Passed(&result_)));
+    callback_ = CompletionCallback();
+    return;
+  }
+
+  for (size_t i = 0; i < paths.size(); ++i) {
+    EntryIsDirectory(profile_, paths[i],
+                     base::Bind(&IsDirectoryCollector::OnIsDirectoryCollected,
+                                weak_ptr_factory_.GetWeakPtr(), i));
+  }
+}
+
+void IsDirectoryCollector::OnIsDirectoryCollected(size_t index,
+                                                  bool is_directory) {
+  if (is_directory)
+    result_->insert(paths_[index]);
+  if (!--left_) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback_, base::Passed(&result_)));
+    // Release the callback to avoid a circullar reference in case an instance
+    // of this class is a member of a ref counted class, which instance is bound
+    // to this callback.
+    callback_ = CompletionCallback();
+  }
+}
+
+}  // namespace app_file_handler_util
+}  // namespace extensions