Migrate HidServiceLinux and HidConnectionLinux to BrowserThread::UI.

extensions/browser/api/hid/hid_connection_resource.h

 // Copyright 2014 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.
 
 #ifndef EXTENSIONS_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_
 #define EXTENSIONS_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "content/public/browser/browser_thread.h"
 #include "device/hid/hid_connection.h"
 #include "extensions/browser/api/api_resource.h"
 #include "extensions/browser/api/api_resource_manager.h"
 
 namespace device {
 class HidConnection;
 }
 
 namespace extensions {
 
 class HidConnectionResource : public ApiResource {
  public:
-#if defined(OS_MACOSX)
-  // Migration from FILE thread to UI thread. OS X gets it first.
+#if defined(OS_WIN)
+  // TODO(reillyg): Migrate Windows backend from FILE thread to UI thread.
+  static const content::BrowserThread::ID kThreadId =
+      content::BrowserThread::FILE;
+#else
   static const content::BrowserThread::ID kThreadId =
       content::BrowserThread::UI;
-#else
-  // TODO(reillyg): Migrate Linux/CrOS and Windows as well.
-  static const content::BrowserThread::ID kThreadId =
-      content::BrowserThread::FILE;
 #endif
 
   HidConnectionResource(const std::string& owner_extension_id,
                         scoped_refptr<device::HidConnection> connection);
   ~HidConnectionResource() override;
 
   scoped_refptr<device::HidConnection> connection() const {
     return connection_;
   }
 
   bool IsPersistent() const override;
 
   static const char* service_name() { return "HidConnectionResourceManager"; }
 
  private:
   scoped_refptr<device::HidConnection> connection_;
 
   DISALLOW_COPY_AND_ASSIGN(HidConnectionResource);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_HID_HID_CONNECTION_RESOURCE_H_