Add extensions code to use common updater in components/update_client/

extensions/browser/updater/update_install_shim.cc

+// Copyright 2015 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 "extensions/browser/updater/update_install_shim.h"
+
+#include "base/files/file_enumerator.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/values.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace extensions {
+
+UpdateInstallShim::UpdateInstallShim(std::string extension_id,
+                                     const base::FilePath& extension_root,
+                                     const UpdateInstallShimCallback& callback)
+    : extension_id_(extension_id),
+      extension_root_(extension_root),
+      callback_(callback) {}
+
+void UpdateInstallShim::OnUpdateError(int error) {
+  VLOG(1) << "OnUpdateError (" << extension_id_ << ") " << error;
+}
+
+bool UpdateInstallShim::Install(const base::DictionaryValue& manifest,
+                                const base::FilePath& unpack_path) {
+  base::ScopedTempDir temp_dir;
+  if (!temp_dir.CreateUniqueTempDir())
+    return false;
+
+  // The UpdateClient code will delete unpack_path if it still exists after
+  // this method is done, so we rename it on top of our temp dir.
+  if (!base::DeleteFile(temp_dir.path(), true) ||

[Sorin Jianu, 2015/10/02 00:05:10]

What is the purpose of the base::DeleteFile call?

[asargent_no_longer_on_chrome, 2015/10/06 21:31:17]

This is for safety, since the base::Move documentation does not guarantee that
it's safe to rename on top of a path that already exists.

[Sorin Jianu, 2015/10/08 22:57:54]

Acknowledged.

+      !base::Move(unpack_path, temp_dir.path())) {
+    LOG(ERROR) << "Trying to install update for " << extension_id_
+               << "and failed to move " << unpack_path.value() << " to  "
+               << temp_dir.path().value();
+    return false;
+  }
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(&UpdateInstallShim::RunCallbackOnUIThread, this,
+                 temp_dir.Take()));
+  return true;
+}
+
+bool UpdateInstallShim::GetInstalledFile(const std::string& file,
+                                         base::FilePath* installed_file) {
+  base::FilePath relative_path = base::FilePath::FromUTF8Unsafe(file);
+  if (relative_path.IsAbsolute() || relative_path.ReferencesParent())
+    return false;
+  *installed_file = extension_root_.Append(relative_path);
+  if (!extension_root_.IsParent(*installed_file) ||
+      !base::PathExists(*installed_file)) {
+    VLOG(1) << "GetInstalledFile failed to find " << installed_file->value();
+    installed_file->clear();
+    return false;
+  }
+  return true;
+}
+
+bool UpdateInstallShim::Uninstall() {
+  NOTREACHED();
+  return false;
+}
+
+UpdateInstallShim::~UpdateInstallShim() {}
+
+void UpdateInstallShim::RunCallbackOnUIThread(const base::FilePath& temp_dir) {
+  if (callback_.is_null()) {
+    content::BrowserThread::PostBlockingPoolTask(
+        FROM_HERE, base::Bind(base::IgnoreResult(&base::DeleteFile), temp_dir,
+                              true /*recursive */));
+    return;
+  }
+  callback_.Run(extension_id_, temp_dir);
+}
+
+}  // namespace extensions