Enable the mojo-based serial API in the renderer behind a flag.

extensions/browser/service_registration_manager.cc

 // 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.
 
 #include "extensions/browser/service_registration_manager.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/site_instance.h"
 #include "device/serial/serial_service_impl.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/process_map.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_api.h"
 #include "extensions/common/switches.h"
 
 namespace extensions {
 namespace {
 
 base::LazyInstance<ServiceRegistrationManager> g_lazy_instance =
     LAZY_INSTANCE_INITIALIZER;
 
+ServiceRegistrationManager* g_test_instance = nullptr;
+
 }  // namespace
 
 ServiceRegistrationManager::ServiceRegistrationManager() {
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableMojoSerialService)) {
     AddServiceFactory(
         "serial",
         base::Bind(device::SerialServiceImpl::CreateOnMessageLoop,
                    content::BrowserThread::GetMessageLoopProxyForThread(
                        content::BrowserThread::FILE),
                    content::BrowserThread::GetMessageLoopProxyForThread(
                        content::BrowserThread::IO),
                    content::BrowserThread::GetMessageLoopProxyForThread(
                        content::BrowserThread::UI)));
   }
 }
 
 ServiceRegistrationManager::~ServiceRegistrationManager() {
 }
 
 ServiceRegistrationManager* ServiceRegistrationManager::GetSharedInstance() {
+  if (g_test_instance)
+    return g_test_instance;
   return g_lazy_instance.Pointer();
 }
 
 void ServiceRegistrationManager::AddServicesToRenderFrame(
     content::RenderFrameHost* render_frame_host) {
   content::BrowserContext* context =
       render_frame_host->GetProcess()->GetBrowserContext();
   content::SiteInstance* site_instance = render_frame_host->GetSiteInstance();
   GURL extension_url = site_instance->GetSiteURL();
   ExtensionRegistry* registry = ExtensionRegistry::Get(context);
 
   // TODO(sammc): Handle content scripts and web pages that have access to some
   // extension APIs.
   if (!extension_url.SchemeIs(kExtensionScheme)) {
     return;
   }
 
   const Extension* extension =
       registry->enabled_extensions().GetByID(extension_url.host());
   DCHECK(extension);
 
   Feature::Context context_type =
       ProcessMap::Get(context)->GetMostLikelyContextType(
           extension, render_frame_host->GetProcess()->GetID());
   for (const auto& factory : factories_) {
     if (ExtensionAPI::GetSharedInstance()
             ->IsAvailable(factory.first, extension, context_type, extension_url)
             .is_available()) {
-      factory.second->Register(render_frame_host->GetServiceRegistry());
+      AddServiceToServiceRegistry(render_frame_host->GetServiceRegistry(),
+                                  factory.second.get());
     }
   }
 }
 
+void ServiceRegistrationManager::AddServiceToServiceRegistry(
+    content::ServiceRegistry* service_registry,
+    internal::ServiceFactoryBase* factory) {
+  factory->Register(service_registry);
+}
+
+// static
+void ServiceRegistrationManager::SetServiceRegistrationManagerForTest(
+    ServiceRegistrationManager* service_registration_manager) {
+  g_test_instance = service_registration_manager;
+}
+
+// static
+void ServiceRegistrationManager::ClearServiceRegistrationManagerForTest() {

[raymes, 2014/10/24 00:09:30]

nit: this isn't really needed right, you could just call
SetServiceRegistrationManagerForTest(NULL)

[Sam McNally, 2014/10/24 03:55:56]

Done.

+  g_test_instance = nullptr;
+}
+
 }  // namespace extensions