FileAPI: Change FileSystemBackend::OpenFileSystem signature

chrome/browser/chromeos/fileapi/file_system_backend.cc

Index: chrome/browser/chromeos/fileapi/file_system_backend.cc
diff --git a/chrome/browser/chromeos/fileapi/file_system_backend.cc b/chrome/browser/chromeos/fileapi/file_system_backend.cc
index 4790e08679438e1781dfb64dab0dfdc9e348fb60..1cc745799142c7ca6a306efb0cbe35444013d644 100644
--- a/chrome/browser/chromeos/fileapi/file_system_backend.cc
+++ b/chrome/browser/chromeos/fileapi/file_system_backend.cc
@@ -106,11 +106,12 @@ bool FileSystemBackend::CanHandleType(fileapi::FileSystemType type) const {
   }
 }
 
-void FileSystemBackend::OpenFileSystem(
+void FileSystemBackend::InitializeFileSystem(
     const GURL& origin_url,
     fileapi::FileSystemType type,
     fileapi::OpenFileSystemMode mode,
-    const OpenFileSystemCallback& callback) {
+    fileapi::FileSystemContext* context,
+    const InitializeFileSystemCallback& callback) {
   DCHECK(fileapi::IsolatedContext::IsIsolatedType(type));
   // Nothing to validate for external filesystem.
   callback.Run(GetFileSystemRootURI(origin_url, type),