[fsp] Do not crash on an invalid modification time.

chrome/browser/chromeos/file_system_provider/operations/get_metadata.cc

 // Copyright 2014 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/browser/chromeos/file_system_provider/operations/get_metadata.h"
 
 #include <string>
 
 #include "chrome/common/extensions/api/file_system_provider.h"
 #include "chrome/common/extensions/api/file_system_provider_internal.h"
@@ skipping 16 matching lines @@
 
   output->is_directory = params->metadata.is_directory;
   output->size = static_cast<int64>(params->metadata.size);
   output->is_symbolic_link = false;  // Not supported.
 
   std::string input_modification_time;
   if (!params->metadata.modification_time.additional_properties.GetString(
           "value", &input_modification_time)) {
     return false;
   }
-  if (!base::Time::FromString(input_modification_time.c_str(),
-                              &output->last_modified)) {
-    return false;
-  }
+
+  // Allow to pass invalid modification time, since there is no way to verify
+  // it easily on any earlier stage.
+  base::Time::FromString(
+      input_modification_time.c_str(), &output->last_modified);
 
   return true;
 }
 
 }  // namespace
 
 GetMetadata::GetMetadata(
     extensions::EventRouter* event_router,
     const ProvidedFileSystemInfo& file_system_info,
     const base::FilePath& directory_path,
@@ skipping 25 matching lines @@
   callback_.Run(base::File::FILE_OK, file_info);
 }
 
 void GetMetadata::OnError(int /* request_id */, base::File::Error error) {
   callback_.Run(error, base::File::Info());
 }
 
 }  // namespace operations
 }  // namespace file_system_provider
 }  // namespace chromeos