Add GetWakeLockWithoutContext() in WakeLockContextProvider mojo interface.

device/wake_lock/wake_lock_context_provider.cc

 // Copyright 2017 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 "device/wake_lock/wake_lock_context_provider.h"
 
 #include <utility>
 
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
@@ skipping 19 matching lines @@
 
 void WakeLockContextProvider::GetWakeLockContextForID(
     int context_id,
     mojo::InterfaceRequest<mojom::WakeLockContext> request) {
   mojo::MakeStrongBinding(
       base::MakeUnique<WakeLockServiceContext>(context_id, file_task_runner_,
                                                native_view_getter_),
       std::move(request));
 }
 
+void WakeLockContextProvider::GetUnassociatedWakeLockContext(
+    mojo::InterfaceRequest<mojom::WakeLockContext> request) {
+  mojo::MakeStrongBinding(base::MakeUnique<WakeLockServiceContext>(
+                              WakeLockServiceContext::WakeLockInvalidContextId,
+                              file_task_runner_, native_view_getter_),
+                          std::move(request));
+}
+
 }  // namespace device