Reorganize accessibility settings.

chrome/browser/ui/webui/settings/chromeos/accessibility_handler.cc

+// Copyright 2016 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/ui/webui/settings/chromeos/accessibility_handler.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/webui/settings_utils.h"

[Dan Beam, 2016/08/02 05:18:47]

what are you using settings_utils.h for?

[dmazzoni, 2016/08/02 17:14:51]

Removed.

+#include "chrome/common/extensions/extension_constants.h"
+#include "content/public/browser/web_ui.h"
+#include "extensions/browser/extension_registry.h"

[Dan Beam, 2016/08/02 05:18:47]

what are you using extension_registry.h for?

[dmazzoni, 2016/08/02 17:14:52]

Kept this in due to your suggestion below, and removed the includes of
extension_service and extension_system instead.

+#include "extensions/browser/extension_system.h"
+
+namespace chromeos {
+namespace settings {
+
+AccessibilityHandler::AccessibilityHandler(content::WebUI* webui)
+    : profile_(Profile::FromWebUI(webui)) {
+}
+
+AccessibilityHandler::~AccessibilityHandler() {}
+
+void AccessibilityHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      "showChromeVoxSettings",
+      base::Bind(&AccessibilityHandler::HandleShowChromeVoxSettings,
+                 base::Unretained(this)));
+}
+
+void AccessibilityHandler::HandleShowChromeVoxSettings(
+    const base::ListValue* args) {
+  ExtensionService* service =
+      extensions::ExtensionSystem::Get(profile_)->extension_service();

[Dan Beam, 2016/08/02 05:18:47]

nit: can the extension system or service ever be null here?

[dmazzoni, 2016/08/02 17:14:52]

I don't believe so, anywhere else in the code doesn't ever
expect it to be null. I added a DCHECK.

+  if (!service->IsExtensionEnabled(extension_misc::kChromeVoxExtensionId))
+    return;
+  const extensions::Extension* extension =
+      service->GetInstalledExtension(extension_misc::kChromeVoxExtensionId);

[Dan Beam, 2016/08/02 05:18:47]

nit: can we use

  Extension* chrome_vox = ExtensionRegistry::Get(profile_)->GetExtensionById(
      extension_misc::kChromeVoxExtensionId,
      extensions::ExtensionRegistry::ENABLED);
  if (!chrome_vox)
    return;

to do the enabled and existence check all at once?

[dmazzoni, 2016/08/02 17:14:51]

Sure, that's cleaner. Thanks.

+  if (!extension)
+    return;
+  extensions::ExtensionTabUtil::OpenOptionsPage(
+      extension,
+      chrome::FindBrowserWithWebContents(web_ui()->GetWebContents()));
+}
+
+}  // namespace settings
+}  // namespace chromeos