[webnfc] Add default implementation for nfc mojo service.

content/browser/frame_host/render_frame_host_impl.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 "content/browser/frame_host/render_frame_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 60 matching lines @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/stream_handle.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/isolated_world_ids.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/common/url_utils.h"
+#include "device/nfc/nfc_impl.h"
 #include "ui/accessibility/ax_tree.h"
 #include "ui/accessibility/ax_tree_update.h"
 #include "ui/gfx/geometry/quad_f.h"
 #include "url/gurl.h"
 
 #if defined(OS_ANDROID)
 #include "content/browser/mojo/service_registrar_android.h"
 #endif
 
 #if defined(OS_MACOSX)
@@ skipping 1838 matching lines @@
 #if defined(OS_CHROMEOS) || defined(OS_ANDROID)
   enable_web_bluetooth = true;
 #endif
 
   if (enable_web_bluetooth) {
     GetServiceRegistry()->AddService(
         base::Bind(&RenderFrameHostImpl::CreateWebBluetoothService,
                    base::Unretained(this)));
   }
 
+  GetServiceRegistry()->AddService(base::Bind(&device::NFCImpl::Create));

[ncarter (slow), 2016/04/26 22:28:26]

Do we plan to implement a c++, non-stub version of NFC on some platform?

If so, then this is fine.

If not, I'd prefer that it be clearer here that the purpose of this line is to
installs a stub implementation (either via comment, or by explicitly
instantiating a stub-looking object like NfcImplDefault()).

[Reilly Grant (use Gerrit), 2016/04/26 22:35:33]

Actually, now that I think about it again I'd rather we not have a stub
implementation at all. If an implementation is not available the Mojo service
binding should simply fail (return from the service factory callback without
binding the interface request).

+
   if (!frame_mojo_shell_)
     frame_mojo_shell_.reset(new FrameMojoShell(this));
 
   GetServiceRegistry()->AddService<shell::mojom::Connector>(base::Bind(
       &FrameMojoShell::BindRequest, base::Unretained(frame_mojo_shell_.get())));
 
 #if defined(ENABLE_WEBVR)
   const base::CommandLine& browser_command_line =
       *base::CommandLine::ForCurrentProcess();
 
@@ skipping 822 matching lines @@
   // handler after it's destroyed so it can't run after the RFHI is destroyed.
   web_bluetooth_service_->SetClientConnectionErrorHandler(base::Bind(
       &RenderFrameHostImpl::DeleteWebBluetoothService, base::Unretained(this)));
 }
 
 void RenderFrameHostImpl::DeleteWebBluetoothService() {
   web_bluetooth_service_.reset();
 }
 
 }  // namespace content