Store USB device permissions in website settings.

chrome/browser/permissions/chooser_permission_context_base.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 "chrome/browser/permissions/chooser_permission_context_base.h"
+
+#include <string>
+
+#include "base/values.h"
+#include "chrome/browser/content_settings/host_content_settings_map_factory.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
+
+const char kObjectListKey[] = "chosen-objects";
+
+ChooserPermissionContextBase::ChooserPermissionContextBase(
+    Profile* profile,
+    const ContentSettingsType permission_type,
+    const ContentSettingsType chooser_settings_type)
+    : host_content_settings_map_(
+          HostContentSettingsMapFactory::GetForProfile(profile)),
+      permission_type_(permission_type),
+      chooser_settings_type_(chooser_settings_type) {
+  DCHECK(host_content_settings_map_);
+}
+
+ChooserPermissionContextBase::~ChooserPermissionContextBase() {}
+
+ChooserPermissionContextBase::ObjectList
+ChooserPermissionContextBase::GetPreviouslyChosenObjects(
+    const GURL& requesting_origin,
+    const GURL& embedding_origin) {
+  ContentSetting content_setting =
+      host_content_settings_map_->GetContentSetting(
+          requesting_origin, embedding_origin, permission_type_, std::string());
+  if (content_setting != CONTENT_SETTING_ALLOW &&
+      content_setting != CONTENT_SETTING_SESSION_ONLY)

[raymes, 2015/10/14 02:07:04]

nit: SESSION_ONLY isn't a possible value for this setting so you can omit it
here

[Reilly Grant (use Gerrit), 2015/10/22 00:57:02]

Done.

+    return ObjectList();
+
+  scoped_ptr<base::DictionaryValue> setting =
+      GetWebsiteSetting(requesting_origin, embedding_origin);
+  scoped_ptr<base::Value> objects;
+  if (!setting->Remove(kObjectListKey, &objects))

[raymes, 2015/10/14 02:07:04]

Hmm maybe I'm misreading but it looks like this dictionary always has just 1 key
which is a base::ListValue. Why not just return a base::ListValue directly from
GetWebsiteSetting/SetWebsiteSetting?

[Reilly Grant (use Gerrit), 2015/10/22 00:57:02]

I need to get the dictionary so that I can replace the list within it and write
the whole thing back to website settings.

+    return ObjectList();
+
+  scoped_ptr<base::ListValue> object_list =
+      base::ListValue::From(objects.Pass());
+  if (!object_list)
+    return ObjectList();
+
+  ObjectList results;
+  for (base::ListValue::iterator it = object_list->begin();
+       it != object_list->end(); ++it) {
+    if ((*it)->GetType() != base::Value::TYPE_DICTIONARY)

[raymes, 2015/10/14 02:07:04]

Should there be a DCHECK here?

[Reilly Grant (use Gerrit), 2015/10/22 00:57:02]

I would rather not DCHECK on invalid data in user preferences.

+      continue;
+
+    scoped_ptr<base::DictionaryValue> object(
+        static_cast<base::DictionaryValue*>(*it));
+    *it = nullptr;
+
+    if (IsValidObject(*object))
+      results.push_back(object.Pass());
+  }
+  return results.Pass();
+}
+
+void ChooserPermissionContextBase::GrantObjectPermission(
+    const GURL& requesting_origin,
+    const GURL& embedding_origin,
+    scoped_ptr<base::DictionaryValue> object) {
+  DCHECK(object && IsValidObject(*object));
+  scoped_ptr<base::DictionaryValue> setting =
+      GetWebsiteSetting(requesting_origin, embedding_origin);
+  base::ListValue* object_list;
+  if (!setting->GetList(kObjectListKey, &object_list)) {
+    object_list = new base::ListValue();
+    setting->Set(kObjectListKey, object_list);
+  }
+  object_list->AppendIfNotPresent(object.release());
+  SetWebsiteSetting(requesting_origin, embedding_origin, setting.Pass());
+}
+
+void ChooserPermissionContextBase::RevokeObjectPermission(
+    const GURL& requesting_origin,
+    const GURL& embedding_origin,
+    const base::DictionaryValue& object) {

[raymes, 2015/10/14 02:07:04]

optional: Maybe just passing a pointer here for consistency?

+  DCHECK(IsValidObject(object));
+  scoped_ptr<base::DictionaryValue> setting =
+      GetWebsiteSetting(requesting_origin, embedding_origin);
+  base::ListValue* object_list;
+  if (!setting->GetList(kObjectListKey, &object_list))
+    return;
+  object_list->Remove(object, nullptr);
+  SetWebsiteSetting(requesting_origin, embedding_origin, setting.Pass());
+}
+
+scoped_ptr<base::DictionaryValue>
+ChooserPermissionContextBase::GetWebsiteSetting(const GURL& requesting_origin,
+                                                const GURL& embedding_origin) {
+  scoped_ptr<base::DictionaryValue> value =
+      base::DictionaryValue::From(host_content_settings_map_->GetWebsiteSetting(
+          requesting_origin, embedding_origin, chooser_settings_type_,
+          std::string(), nullptr));
+  if (!value)
+    return make_scoped_ptr(new base::DictionaryValue());
+
+  return value.Pass();
+}
+
+void ChooserPermissionContextBase::SetWebsiteSetting(
+    const GURL& requesting_origin,
+    const GURL& embedding_origin,
+    scoped_ptr<base::Value> value) {
+  ContentSettingsPattern primary_pattern(
+      ContentSettingsPattern::FromURLNoWildcard(requesting_origin));
+  ContentSettingsPattern secondary_pattern(
+      ContentSettingsPattern::FromURLNoWildcard(embedding_origin));
+  if (!primary_pattern.IsValid() || !secondary_pattern.IsValid())
+    return;
+
+  host_content_settings_map_->SetWebsiteSetting(
+      primary_pattern, secondary_pattern, chooser_settings_type_, std::string(),
+      value.release());
+}