Add schema chrome-extension-resource:// for extension resources

chrome/common/extensions/extension_file_util.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/common/extensions/extension_file_util.h"
 
 #include <map>
 #include <vector>
 
 #include "base/file_util.h"
@@ skipping 617 matching lines @@
 
   // 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 FilePath();
 
   return path;
 }
 
+FilePath ExtensionResourceURLToFilePath(const GURL& url, const FilePath& root) {
+  std::string host = net::UnescapeURLComponent(url.host(),
+      net::UnescapeRule::SPACES | net::UnescapeRule::URL_SPECIAL_CHARS);
+  if (host.empty())
+    return FilePath();
+
+  FilePath relative_path = ExtensionURLToRelativeFilePath(url);
+  if (relative_path.empty())
+    return FilePath();
+
+  FilePath path = root.AppendASCII(host).Append(relative_path);
+  if (!file_util::PathExists(path) ||
+      !file_util::AbsolutePath(&path) ||
+      !root.IsParent(path)) {
+    return FilePath();
+  }
+  return path;
+}
+
 FilePath GetUserDataTempDir() {
   // We do file IO in this function, but only when the current profile's
   // Temp directory has never been used before, or in a rare error case.
   // Developers are not likely to see these situations often, so do an
   // explicit thread check.
   base::ThreadRestrictions::AssertIOAllowed();
 
   // The following enum used to be sent as a histogram to diagnose issues
   // accessing the temp path (crbug/70056).  The histogram is gone, but
   // the enum makes it clear exactly why the temp directory can not be
@@ skipping 49 matching lines @@
     return temp_path;
 
   return FilePath();
 }
 
 void DeleteFile(const FilePath& path, bool recursive) {
   file_util::Delete(path, recursive);
 }
 
 }  // namespace extension_file_util