Add systeminfo.storage API implementation skeleton

chrome/browser/extensions/api/systeminfo_storage/systeminfo_storage_api.cc

+// Copyright (c) 2012 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/extensions/api/systeminfo_storage/systeminfo_storage_api.h"
+
+#include "base/logging.h"
+#include "base/json/json_writer.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/string_number_conversions.h"
+#include "base/string_piece.h"
+#include "base/values.h"
+#include "content/public/browser/browser_thread.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/api/systeminfo_storage/storage_info_provider.h"
+
+namespace extensions {
+using content::BrowserThread;
+
+SysteminfoStorageGetFunction::SysteminfoStorageGetFunction() {
+}
+
+SysteminfoStorageGetFunction::~SysteminfoStorageGetFunction() {
+}
+
+bool SysteminfoStorageGetFunction::RunImpl() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
+    base::Bind(&SysteminfoStorageGetFunction::WorkOnFileThread, this));

[James Hawkins, 2012/08/09 15:47:34]

nit: Start of parameter rows must align on the same column.

[Hongbo Min, 2012/08/12 03:31:58]

Done.

+  return true;
+}
+
+void SysteminfoStorageGetFunction::WorkOnFileThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  bool success = false;
+  scoped_ptr<StorageInfoProvider> provider(StorageInfoProvider::Create());
+  StorageInfo info;
+  if (provider.get() && provider->GetStorageInfo(&info)) {

[James Hawkins, 2012/08/09 15:47:34]

Why would provider.get() ever be non-NULL?

[Hongbo Min, 2012/08/10 02:43:29]

In case of out of memory, the allocation for provider fails.
On 2012/08/09 15:47:34, James Hawkins wrote:

[James Hawkins, 2012/08/11 16:37:54]

Chrome code does not check for OOM situations, so the check should be removed.

+    SetResult(info.ToValue().release());
+    success = true;
+  } else {
+    SetError("Error in querying storage information");
+    success = false;

[James Hawkins, 2012/08/09 15:47:34]

nit: This line is redundant with line 34.

[Hongbo Min, 2012/08/12 03:31:58]

Done.

+  }
+
+  // Response on UI thread

[James Hawkins, 2012/08/09 15:47:34]

nit: Comments must end with a period.

[Hongbo Min, 2012/08/12 03:31:58]

Done.

+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+          base::Bind(&SysteminfoStorageGetFunction::RespondOnUIThread,

[James Hawkins, 2012/08/09 15:47:34]

nit: Alignment is off.

[Hongbo Min, 2012/08/12 03:31:58]

Done.

+              this, success));
+}
+
+void SysteminfoStorageGetFunction::RespondOnUIThread(bool success) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  SendResponse(success);
+}
+
+} // namespace extensions