[fsp] Introduce chrome://fsp-internals for logging and debugging.

chrome/browser/chromeos/file_system_provider/request_manager.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/request_manager.h"
 
 #include "base/files/file.h"
 #include "base/stl_util.h"
 
 namespace chromeos {
@@ skipping 89 matching lines @@
 }
 
 void RequestManager::SetTimeoutForTests(const base::TimeDelta& timeout) {
   timeout_ = timeout;
 }
 
 void RequestManager::OnRequestTimeout(int request_id) {
   RejectRequest(request_id, base::File::FILE_ERROR_ABORT);
 }
 
+size_t RequestManager::GetActiveRequestsForLogging() const {
+  return requests_.size();
+}
+
 RequestManager::Request::Request() {}
 
 RequestManager::Request::~Request() {}
 
 }  // namespace file_system_provider
 }  // namespace chromeos