Set drive as the default download folder

chrome/browser/download/download_dir_policy_handler.cc

 // Copyright 2013 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/download/download_dir_policy_handler.h"
 
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_value_map.h"
 #include "base/values.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/policy/policy_path_parser.h"
 #include "chrome/common/pref_names.h"
+#include "components/policy/core/browser/configuration_policy_handler_parameters.h"
+#include "components/policy/core/browser/policy_error_map.h"
 #include "components/policy/core/common/policy_map.h"
+#include "components/policy/core/common/policy_types.h"
+#include "grit/component_strings.h"
 #include "policy/policy_constants.h"
 
+#if defined(OS_CHROMEOS)
+#include "chrome/browser/chromeos/drive/file_system_util.h"
+#endif
+
+namespace {
+#if defined(OS_CHROMEOS)
+const char* kDriveNamePolicyVariableName = "${google_drive}";
+
+// Drive root folder relative to its mount point.
+const base::FilePath::CharType* kRootRelativeToDriveMount =
+    FILE_PATH_LITERAL("/root/");
+#endif
+}  // namespace
+
 DownloadDirPolicyHandler::DownloadDirPolicyHandler()
     : TypeCheckingPolicyHandler(policy::key::kDownloadDirectory,
                                 base::Value::TYPE_STRING) {}
 
 DownloadDirPolicyHandler::~DownloadDirPolicyHandler() {}
 
-void DownloadDirPolicyHandler::ApplyPolicySettings(
+bool DownloadDirPolicyHandler::CheckPolicySettings(
     const policy::PolicyMap& policies,
+    policy::PolicyErrorMap* errors) {
+  const base::Value* value = NULL;
+  if (!CheckAndGetValue(policies, errors, &value))
+    return false;
+
+#if defined(OS_CHROMEOS)
+  // Download directory can only be set as a user policy. If it is set through
+  // platform policy for a chromeos=1 build, ignore it.
+  if (value &&
+      policies.Get(policy_name())->scope != policy::POLICY_SCOPE_USER) {
+    errors->AddError(policy_name(), IDS_POLICY_SCOPE_ERROR);
+    return false;
+  }
+#endif
+
+  return true;
+}
+
+void DownloadDirPolicyHandler::ApplyPolicySettingsWithParameters(
+    const policy::PolicyMap& policies,
+    const policy::PolicyHandlerParameters& parameters,
     PrefValueMap* prefs) {
   const base::Value* value = policies.GetValue(policy_name());
   base::FilePath::StringType string_value;
   if (!value || !value->GetAsString(&string_value))
     return;
 
-  base::FilePath::StringType expanded_value =
-      policy::path_parser::ExpandPathVariables(string_value);
+  base::FilePath::StringType expanded_value;
+#if defined(OS_CHROMEOS)
+  // TODO(kaliamoorthi): cleanup policy::path_parser and fold this code

[bartfab (slow), 2014/03/14 16:16:45]

Nit: s/cleanup/Clean up/

+  // into it. http://crbug.com/352627
+  size_t position = string_value.find(kDriveNamePolicyVariableName);
+  if (position != base::FilePath::StringType::npos) {
+    base::FilePath::StringType google_drive_root;
+    if (!parameters.user_id_hash.empty()) {
+      google_drive_root = drive::util::GetDriveMountPointPathForUserIdHash(

[bartfab (slow), 2014/03/14 16:16:45]

Nit: A better way to do this is
GetDriveMountPointPathForUserIdHash(parameters.user_id_hash).Append(kRootRelativeToDriveMount).value()

+                              parameters.user_id_hash).value() +
+                          kRootRelativeToDriveMount;
+    }
+    expanded_value = string_value.replace(
+        position,
+        base::FilePath::StringType(kDriveNamePolicyVariableName).length(),
+        google_drive_root);
+  }
+#else
+  expanded_value = policy::path_parser::ExpandPathVariables(string_value);
+#endif
   // Make sure the path isn't empty, since that will point to an undefined
   // location; the default location is used instead in that case.
   // This is checked after path expansion because a non-empty policy value can
   // lead to an empty path value after expansion (e.g. "\"\"").
   if (expanded_value.empty())
     expanded_value = DownloadPrefs::GetDefaultDownloadDirectory().value();
   prefs->SetValue(prefs::kDownloadDefaultDirectory,
                   base::Value::CreateStringValue(expanded_value));
-  prefs->SetValue(prefs::kPromptForDownload,
-                  base::Value::CreateBooleanValue(false));
+  if (policies.Get(policy_name())->level == policy::POLICY_LEVEL_MANDATORY)

[bartfab (slow), 2014/03/14 16:16:45]

Nit 1: Multi-line conditionals require curly braces.
Nit 2: Please add a comment explaining why this is done for mandatory level
only.

+    prefs->SetValue(prefs::kPromptForDownload,
+                    base::Value::CreateBooleanValue(false));
 }