browser_test that creates filesystem resources in extension origin

content/public/test/test_fileapi_operation_waiter.cc

+// Copyright 2016 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 "content/public/test/test_fileapi_operation_waiter.h"
+
+#include "base/bind_helpers.h"
+#include "base/lazy_instance.h"
+#include "base/observer_list.h"
+#include "content/public/browser/browser_thread.h"
+#include "storage/browser/fileapi/file_system_context.h"
+#include "storage/browser/fileapi/sandbox_file_system_backend_delegate.h"
+
+namespace content {
+
+using storage::FileSystemContext;
+using storage::FileSystemURL;
+using storage::FileUpdateObserver;
+
+namespace {
+
+// Because of how fileapi internally creates copies of its observer lists,
+// removing an observer is not a supported operation. So to support temporary,
+// test-style observers, we create one long-lived global observer instance that
+// dispatches to a list of short-lived observers.
+//
+// This object operates on the UI thread, though it registers itself as an
+// observer on the IO thread.
+class FileUpdateObserverMultiplexer : public FileUpdateObserver {
+ public:
+  FileUpdateObserverMultiplexer() {}
+
+  void AddObserver(FileSystemContext* context, FileUpdateObserver* observer) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+    // On first initialization, install ourself as an observer. We never
+    // uninstall, because we expect to leak.
+    if (!context_) {
+      // Currently we only listen to kFileSystemTypeTemporary; it should be fine
+      // to add other filesystem types as needed.
+      context_ = context;
+      base::Closure task = base::Bind(
+          &storage::SandboxFileSystemBackendDelegate::AddFileUpdateObserver,
+          base::Unretained(context_->sandbox_delegate()),
+          storage::kFileSystemTypeTemporary, base::Unretained(this),
+          base::RetainedRef(
+              BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)));
+      BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, task);
+    }
+
+    CHECK_EQ(context, context_) << "Multiprofile is not implemented";
+
+    observers_.AddObserver(observer);
+  }
+
+  void RemoveObserver(FileUpdateObserver* observer) {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    observers_.RemoveObserver(observer);
+  }
+
+  // FileUpdateObserver overrides:
+  void OnStartUpdate(const FileSystemURL& url) override {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    for (auto& observer : observers_)
+      observer.OnStartUpdate(url);
+  }
+  void OnUpdate(const FileSystemURL& url, int64_t delta) override {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    for (auto& observer : observers_)
+      observer.OnUpdate(url, delta);
+  }
+  void OnEndUpdate(const FileSystemURL& url) override {
+    DCHECK_CURRENTLY_ON(BrowserThread::UI);
+    for (auto& observer : observers_)
+      observer.OnEndUpdate(url);
+  }
+
+ private:
+  FileSystemContext* context_ = nullptr;
+  base::ObserverList<FileUpdateObserver> observers_;
+  DISALLOW_COPY_AND_ASSIGN(FileUpdateObserverMultiplexer);
+};
+
+static base::LazyInstance<FileUpdateObserverMultiplexer>::Leaky g_multiplexer =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+TestFileapiOperationWaiter::TestFileapiOperationWaiter(
+    FileSystemContext* context) {
+  g_multiplexer.Get().AddObserver(context, this);
+}
+
+TestFileapiOperationWaiter::~TestFileapiOperationWaiter() {
+  g_multiplexer.Get().RemoveObserver(this);
+}
+
+void TestFileapiOperationWaiter::WaitForEndUpdate() {
+  run_loop_.Run();
+}
+
+void TestFileapiOperationWaiter::OnStartUpdate(const FileSystemURL& url) {
+  did_start_update_ = true;
+}
+
+void TestFileapiOperationWaiter::OnUpdate(const FileSystemURL& url,
+                                          int64_t delta) {}
+
+void TestFileapiOperationWaiter::OnEndUpdate(const FileSystemURL& url) {
+  run_loop_.Quit();
+}
+
+}  // namespace content