(2nd try) Add a helper class that keeps per-profile information for FileSystem API

chrome/browser/file_system/file_system_host_context.cc

+// Copyright (c) 2010 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/file_system/file_system_host_context.h"
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/profile.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebFileSystem.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebCString.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebSecurityOrigin.h"
+
+const FilePath::CharType FileSystemHostContext::kFileSystemDirectory[] =
+    FILE_PATH_LITERAL("FileSystem");
+
+const char FileSystemHostContext::kPersistentName[] = "Persistent";
+const char FileSystemHostContext::kTemporaryName[] = "Temporary";
+
+FileSystemHostContext::FileSystemHostContext(
+    const FilePath& data_path, bool is_incognito)
+    : base_path_(data_path.Append(kFileSystemDirectory)),
+      is_incognito_(is_incognito) {
+}
+
+bool FileSystemHostContext::GetFileSystemRootPath(
+    const GURL& origin_url, WebKit::WebFileSystem::Type type,
+    FilePath* root_path, std::string* name) const {
+  // TODO(kinuko): should return an isolated temporary file system space.
+  if (is_incognito_)
+    return false;
+  std::string storage_identifier = GetStorageIdentifierFromURL(origin_url);
+  switch (type) {
+    case WebKit::WebFileSystem::TypeTemporary:
+      if (root_path)
+        *root_path = base_path_.AppendASCII(storage_identifier)
+                               .AppendASCII(kTemporaryName);
+      if (name)
+        *name = storage_identifier + ":" + kTemporaryName;
+      return true;
+    case WebKit::WebFileSystem::TypePersistent:
+      if (root_path)
+        *root_path = base_path_.AppendASCII(storage_identifier)
+                               .AppendASCII(kPersistentName);
+      if (name)
+        *name = storage_identifier + ":" + kPersistentName;
+      return true;
+  }
+  LOG(WARNING) << "Unknown filesystem type is requested:" << type;
+  return false;
+}
+
+bool FileSystemHostContext::CheckValidFileSystemPath(
+    const FilePath& path) const {
+  // Any paths that includes parent references are considered invalid.
+  return !path.ReferencesParent() && base_path_.IsParent(path);
+}
+
+std::string FileSystemHostContext::GetStorageIdentifierFromURL(
+    const GURL& url) {
+  WebKit::WebSecurityOrigin web_security_origin =
+      WebKit::WebSecurityOrigin::createFromString(UTF8ToUTF16(url.spec()));
+  return web_security_origin.databaseIdentifier().utf8();
+}