kFileSystemTypeIsolated should be only used in the URL exposed to renderer

webkit/chromeos/fileapi/cros_mount_point_provider.cc

Index: webkit/chromeos/fileapi/cros_mount_point_provider.cc
diff --git a/webkit/chromeos/fileapi/cros_mount_point_provider.cc b/webkit/chromeos/fileapi/cros_mount_point_provider.cc
index ff5b40183dbadb948f5ef8a3666e9845c952c258..79642c4164597b2424345dedc015d8662e952e6d 100644
--- a/webkit/chromeos/fileapi/cros_mount_point_provider.cc
+++ b/webkit/chromeos/fileapi/cros_mount_point_provider.cc
@@ -65,8 +65,8 @@ void CrosMountPointProvider::ValidateFileSystemRoot(
     fileapi::FileSystemType type,
     bool create,
     const ValidateFileSystemCallback& callback) {
+  DCHECK(fileapi::IsolatedContext::IsIsolatedType(type));
   // Nothing to validate for external filesystem.
-  DCHECK(type == fileapi::kFileSystemTypeExternal);
   callback.Run(base::PLATFORM_FILE_OK);
 }
 
@@ -75,7 +75,7 @@ FilePath CrosMountPointProvider::GetFileSystemRootPathOnFileThread(
     fileapi::FileSystemType type,
     const FilePath& virtual_path,
     bool create) {
-  DCHECK(type == fileapi::kFileSystemTypeExternal);
+  DCHECK(fileapi::IsolatedContext::IsIsolatedType(type));
   fileapi::FileSystemURL url(origin_url, type, virtual_path);
   if (!url.is_valid())
     return FilePath();
@@ -89,12 +89,13 @@ FilePath CrosMountPointProvider::GetFileSystemRootPathOnFileThread(
 
 bool CrosMountPointProvider::IsAccessAllowed(
     const fileapi::FileSystemURL& url) {
-  // TODO(kinuko): this should call CanHandleURL() once
-  // http://crbug.com/142267 is fixed.
-  if (url.type() != fileapi::kFileSystemTypeNativeLocal &&
-      url.type() != fileapi::kFileSystemTypeDrive)
+  if (!CanHandleURL(url))
     return false;
 
+  // No extra check is needed for isolated file systems.
+  if (url.mount_type() == fileapi::kFileSystemTypeIsolated)
+    return true;
+
   // Permit access to mount points from internal WebUI.
   const GURL& origin_url = url.origin();
   if (origin_url.SchemeIs(kChromeUIScheme))