Move chrome/common/extensions/background_info.h to src/extensions

extensions/common/file_util.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 "extensions/common/file_util.h"
+
+#include <string>
+
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "net/base/escape.h"
+#include "url/gurl.h"
+
+namespace extensions {
+namespace file_util {
+
+base::FilePath ExtensionURLToRelativeFilePath(const GURL& url) {
+  std::string url_path = url.path();
+  if (url_path.empty() || url_path[0] != '/')
+    return base::FilePath();
+
+  // Drop the leading slashes and convert %-encoded UTF8 to regular UTF8.
+  std::string file_path = net::UnescapeURLComponent(url_path,
+      net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
+  size_t skip = file_path.find_first_not_of("/\\");
+  if (skip != file_path.npos)
+    file_path = file_path.substr(skip);
+
+  base::FilePath path = base::FilePath::FromUTF8Unsafe(file_path);
+
+  // It's still possible for someone to construct an annoying URL whose path
+  // would still wind up not being considered relative at this point.
+  // For example: chrome-extension://id/c:////foo.html
+  if (path.IsAbsolute())
+    return base::FilePath();
+
+  return path;
+}
+
+base::FilePath ExtensionResourceURLToFilePath(const GURL& url,
+                                              const base::FilePath& root) {
+  std::string host = net::UnescapeURLComponent(url.host(),
+      net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
+  if (host.empty())
+    return base::FilePath();
+
+  base::FilePath relative_path = ExtensionURLToRelativeFilePath(url);
+  if (relative_path.empty())
+    return base::FilePath();
+
+  base::FilePath path = root.AppendASCII(host).Append(relative_path);
+  if (!base::PathExists(path))
+    return base::FilePath();
+  path = base::MakeAbsoluteFilePath(path);
+  if (path.empty() || !root.IsParent(path))
+    return base::FilePath();
+  return path;
+}
+
+}  // namespace file_util
+}  // namespace extensions