Extract external file systems handling from isolated context.

webkit/fileapi/file_system_url.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 "webkit/fileapi/file_system_url.h"
 
 #include <sstream>
 
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "net/base/escape.h"
+#include "webkit/fileapi/external_mount_points.h"
 #include "webkit/fileapi/file_system_types.h"
 #include "webkit/fileapi/file_system_util.h"
 #include "webkit/fileapi/isolated_context.h"
 
 namespace fileapi {
 
 namespace {
 
 bool CrackFileSystemURL(
     const GURL& url,
@@ skipping 129 matching lines @@
     return lhs.filesystem_id_ < rhs.filesystem_id_;
   return lhs.path_ < rhs.path_;
 }
 
 void FileSystemURL::MayCrackIsolatedPath() {
   path_ = virtual_path_;
   mount_type_ = type_;
   if (is_valid_ && IsolatedContext::IsIsolatedType(type_)) {
     // If the type is isolated, crack the path further to get the 'real'
     // filesystem type and path.
-    is_valid_ = IsolatedContext::GetInstance()->CrackIsolatedPath(
+    is_valid_ = ExternalMountPoints::GetSystemInstance()->CrackVirtualPath(
+        virtual_path_, &filesystem_id_, &type_, &path_);
+    if (is_valid_)
+      return;
+    is_valid_ = IsolatedContext::GetInstance()->CrackVirtualPath(
         virtual_path_, &filesystem_id_, &type_, &path_);
   }
 }
 
 }  // namespace fileapi