Add service registration for apps APIs implemented as mojo services.

This adds a ServiceRegistrationManager that acts as a global repository
of extensions API services to be added to RenderFrameHosts along with
the extensions API permissions that gate access to them.

BUG=389016

Review URL: https://codereview.chromium.org/652793002

Cr-Commit-Position: refs/heads/master@{#301310}

2 files changed, 177 insertions, 0 deletions

diff --git a/extensions/browser/mojo/service_registration_manager.cc b/extensions/browser/mojo/service_registration_manager.cc
new file mode 100644
index 0000000..97f3698
--- /dev/null
+++ b/extensions/browser/mojo/service_registration_manager.cc
@@ -0,0 +1,80 @@
+// 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/mojo/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;
+
+}  // 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() {
+  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());
+  if (!extension)
+    return;
+
+  Feature::Context context_type =
+      ProcessMap::Get(context)->GetMostLikelyContextType(
+          extension, render_frame_host->GetProcess()->GetID());
+  for (const auto& factory : factories_) {
+    auto availability = ExtensionAPI::GetSharedInstance()->IsAvailable(
+        factory.first, extension, context_type, extension_url);
+    if (availability.is_available())
+      factory.second->Register(render_frame_host->GetServiceRegistry());
+  }
+}
+
+}  // namespace extensions
diff --git a/extensions/browser/mojo/service_registration_manager.h b/extensions/browser/mojo/service_registration_manager.h
new file mode 100644
index 0000000..c7d14c6
--- /dev/null
+++ b/extensions/browser/mojo/service_registration_manager.h
@@ -0,0 +1,97 @@
+// 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_MOJO_SERVICE_REGISTRATION_MANAGER_H_
+#define EXTENSIONS_BROWSER_MOJO_SERVICE_REGISTRATION_MANAGER_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/linked_ptr.h"
+#include "content/public/common/service_registry.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+
+namespace content {
+class RenderFrameHost;
+}
+
+namespace extensions {
+namespace internal {
+
+// A base class for forwarding calls to ServiceRegistry::AddService().
+class ServiceFactoryBase {
+ public:
+  virtual ~ServiceFactoryBase() {}
+
+  // Add this service factory to |service_registry|.
+  virtual void Register(content::ServiceRegistry* service_registry) const = 0;
+};
+
+template <typename Interface>
+class ServiceFactory : public ServiceFactoryBase {
+ public:
+  explicit ServiceFactory(
+      const base::Callback<void(mojo::InterfaceRequest<Interface>)>& factory)
+      : factory_(factory) {}
+  ~ServiceFactory() override {}
+
+  void Register(content::ServiceRegistry* service_registry) const override {
+    service_registry->AddService(factory_);
+  }
+
+ private:
+  const base::Callback<void(mojo::InterfaceRequest<Interface>)> factory_;
+  DISALLOW_COPY_AND_ASSIGN(ServiceFactory);
+};
+
+}  // namespace internal
+
+// A meta service registry. This allows registration of service factories and
+// their associated extensions API permission name. Whenever a RenderFrameHost
+// is created, each service that the render frame should have access to (based
+// on its SiteInstance), is added to the ServiceRegistry for that
+// RenderFrameHost.
+class ServiceRegistrationManager {
+ public:
+  ServiceRegistrationManager();
+  ~ServiceRegistrationManager();
+
+  static ServiceRegistrationManager* GetSharedInstance();
+
+  // Registers a ServiceFactory to be provided to extensions with the
+  // |permission_name| API permission.
+  //
+  // TODO(sammc): Add support for service factories that take the Extension*
+  // (or extension ID) and BrowserContext to allow fine-grained service and
+  // permission customization.
+  //
+  // TODO(sammc): Support more flexible service filters than just API permission
+  // names.
+  template <typename Interface>
+  void AddServiceFactory(
+      const std::string& permission_name,
+      const base::Callback<void(mojo::InterfaceRequest<Interface>)>& factory) {
+    factories_.push_back(
+        std::make_pair(permission_name,
+                       linked_ptr<internal::ServiceFactoryBase>(
+                           new internal::ServiceFactory<Interface>(factory))));
+  }
+
+  // Adds the service factories appropriate for |render_frame_host| to its
+  // ServiceRegistry.
+  void AddServicesToRenderFrame(content::RenderFrameHost* render_frame_host);
+
+ private:
+  // All factories and their corresponding API permissions.
+  std::vector<std::pair<std::string, linked_ptr<internal::ServiceFactoryBase>>>
+      factories_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceRegistrationManager);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_MOJO_SERVICE_REGISTRATION_MANAGER_H_