extensions/renderer/ipc_message_sender.cc - chromium/src - Git at Google

 // 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 "extensions/renderer/ipc_message_sender.h"

 #include <map>

 #include "base/guid.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/optional.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/worker_thread.h"
 #include "extensions/common/api/messaging/messaging_endpoint.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/features/feature.h"
 #include "extensions/renderer/message_target.h"
 #include "extensions/renderer/script_context.h"
 #include "extensions/renderer/worker_thread_dispatcher.h"
 #include "third_party/blink/public/mojom/service_worker/service_worker_registration.mojom.h"

 namespace extensions {

 namespace {

 // These values are logged to UMA. Entries should not be renumbered.
 enum class IncludeTlsChannelIdBehavior {
   // The TLS channel ID was not requested.
   kNotRequested = 0,

   // DEPRECATED: The TLS channel ID was requested, but was not included because
   // the target extension did not allow it.
   // kRequestedButDenied = 1,
   // DEPRECATED: The TLS channel ID was requested, but was not found.
   // kRequestedButNotFound = 2,
   // DEPRECATED: The TLS channel ID was requested, allowed, and included in the
   // response.
   // kRequestedAndIncluded = 3,

   // The TLS channel ID was requested, but was not provided because Channel ID
   // is no longer supported.
   kRequestedButNotSupported = 4,

   kMaxValue = kRequestedButNotSupported,
 };

 void RecordIncludeTlsChannelIdBehavior(bool include_tls_channel_id) {
   auto tls_channel_id_behavior =
       include_tls_channel_id
           ? IncludeTlsChannelIdBehavior::kRequestedButNotSupported
           : IncludeTlsChannelIdBehavior::kNotRequested;
   UMA_HISTOGRAM_ENUMERATION("Extensions.Messaging.IncludeChannelIdBehavior",
                             tls_channel_id_behavior);
 }

 class MainThreadIPCMessageSender : public IPCMessageSender {
  public:
   MainThreadIPCMessageSender() : render_thread_(content::RenderThread::Get()) {}
   ~MainThreadIPCMessageSender() override {}

   void SendRequestIPC(ScriptContext* context,
                       std::unique_ptr<ExtensionHostMsg_Request_Params> params,
                       binding::RequestThread thread) override {
     content::RenderFrame* frame = context->GetRenderFrame();
     if (!frame)
       return;

     switch (thread) {
       case binding::RequestThread::UI:
         frame->Send(
             new ExtensionHostMsg_Request(frame->GetRoutingID(), *params));
         break;
       case binding::RequestThread::IO:
         frame->Send(new ExtensionHostMsg_RequestForIOThread(
             frame->GetRoutingID(), *params));
         break;
     }
   }

   void SendOnRequestResponseReceivedIPC(int request_id) override {}

   void SendAddUnfilteredEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_AddListener(
         context->GetExtensionID(), context->url(), event_name,
         blink::mojom::kInvalidServiceWorkerVersionId, kMainThreadId));
   }

   void SendRemoveUnfilteredEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_RemoveListener(
         context->GetExtensionID(), context->url(), event_name,
         blink::mojom::kInvalidServiceWorkerVersionId, kMainThreadId));
   }

   void SendAddUnfilteredLazyEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_AddLazyListener(
         context->GetExtensionID(), event_name));
   }

   void SendRemoveUnfilteredLazyEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_RemoveLazyListener(
         context->GetExtensionID(), event_name));
   }

   void SendAddFilteredEventListenerIPC(ScriptContext* context,
                                        const std::string& event_name,
                                        const base::DictionaryValue& filter,
                                        bool is_lazy) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_AddFilteredListener(
         context->GetExtensionID(), event_name, base::nullopt, filter, is_lazy));
   }

   void SendRemoveFilteredEventListenerIPC(ScriptContext* context,
                                           const std::string& event_name,
                                           const base::DictionaryValue& filter,
                                           bool remove_lazy_listener) override {
     DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

     render_thread_->Send(new ExtensionHostMsg_RemoveFilteredListener(
         context->GetExtensionID(), event_name, base::nullopt, filter,
         remove_lazy_listener));
   }

   void SendOpenMessageChannel(ScriptContext* script_context,
                               const PortId& port_id,
                               const MessageTarget& target,
                               const std::string& channel_name,
                               bool include_tls_channel_id) override {
     RecordIncludeTlsChannelIdBehavior(include_tls_channel_id);
     content::RenderFrame* render_frame = script_context->GetRenderFrame();
     DCHECK(render_frame);
     PortContext frame_context =
         PortContext::ForFrame(render_frame->GetRoutingID());
     const Extension* extension = script_context->extension();

     switch (target.type) {
       case MessageTarget::EXTENSION: {
         ExtensionMsg_ExternalConnectionInfo info;
         if (extension && !extension->is_hosted_app()) {
           info.source_endpoint =
               script_context->context_type() == Feature::CONTENT_SCRIPT_CONTEXT
                   ? MessagingEndpoint::ForContentScript(extension->id())
                   : MessagingEndpoint::ForExtension(extension->id());
         } else {
           info.source_endpoint = MessagingEndpoint::ForWebPage();
         }
         info.target_id = *target.extension_id;
         info.source_url = script_context->url();

         render_thread_->Send(new ExtensionHostMsg_OpenChannelToExtension(
             frame_context, info, channel_name, port_id));
         break;
       }
       case MessageTarget::TAB: {
         DCHECK(extension);
         DCHECK_NE(script_context->context_type(),
                   Feature::CONTENT_SCRIPT_CONTEXT);
         ExtensionMsg_TabTargetConnectionInfo info;
         info.tab_id = *target.tab_id;
         info.frame_id = *target.frame_id;
         render_frame->Send(new ExtensionHostMsg_OpenChannelToTab(
             frame_context, info, extension->id(), channel_name, port_id));
         break;
       }
       case MessageTarget::NATIVE_APP:
         render_frame->Send(new ExtensionHostMsg_OpenChannelToNativeApp(
             frame_context, *target.native_application_name, port_id));
         break;
     }
   }

   void SendOpenMessagePort(int routing_id, const PortId& port_id) override {
     render_thread_->Send(new ExtensionHostMsg_OpenMessagePort(
         PortContext::ForFrame(routing_id), port_id));
   }

   void SendCloseMessagePort(int routing_id,
                             const PortId& port_id,
                             bool close_channel) override {
     render_thread_->Send(new ExtensionHostMsg_CloseMessagePort(
         PortContext::ForFrame(routing_id), port_id, close_channel));
   }

   void SendPostMessageToPort(const PortId& port_id,
                              const Message& message) override {
     render_thread_->Send(new ExtensionHostMsg_PostMessage(port_id, message));
   }

  private:
   content::RenderThread* const render_thread_;

   DISALLOW_COPY_AND_ASSIGN(MainThreadIPCMessageSender);
 };

 class WorkerThreadIPCMessageSender : public IPCMessageSender {
  public:
   WorkerThreadIPCMessageSender(WorkerThreadDispatcher* dispatcher,
                                int64_t service_worker_version_id)
       : dispatcher_(dispatcher),
         service_worker_version_id_(service_worker_version_id) {}
   ~WorkerThreadIPCMessageSender() override {}

   void SendRequestIPC(ScriptContext* context,
                       std::unique_ptr<ExtensionHostMsg_Request_Params> params,
                       binding::RequestThread thread) override {
     DCHECK(!context->GetRenderFrame());
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_EQ(binding::RequestThread::UI, thread);
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

     int worker_thread_id = content::WorkerThread::GetCurrentId();
     params->worker_thread_id = worker_thread_id;
     params->service_worker_version_id = service_worker_version_id_;

     std::string guid = base::GenerateGUID();
     request_id_to_guid_[params->request_id] = guid;

     // Keeps the worker alive during extension function call. Balanced in
     // HandleWorkerResponse().
     dispatcher_->Send(new ExtensionHostMsg_IncrementServiceWorkerActivity(
         service_worker_version_id_, guid));

     dispatcher_->Send(new ExtensionHostMsg_RequestWorker(*params));
   }

   void SendOnRequestResponseReceivedIPC(int request_id) override {
     auto iter = request_id_to_guid_.find(request_id);
     DCHECK(iter != request_id_to_guid_.end());
     dispatcher_->Send(new ExtensionHostMsg_DecrementServiceWorkerActivity(
         service_worker_version_id_, iter->second));
     request_id_to_guid_.erase(iter);
   }

   void SendAddUnfilteredEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
     DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
               context->service_worker_version_id());

     dispatcher_->Send(new ExtensionHostMsg_AddListener(
         context->GetExtensionID(), context->service_worker_scope(), event_name,
         context->service_worker_version_id(),
         content::WorkerThread::GetCurrentId()));
   }

   void SendRemoveUnfilteredEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
     DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
               context->service_worker_version_id());

     dispatcher_->Send(new ExtensionHostMsg_RemoveListener(
         context->GetExtensionID(), context->service_worker_scope(), event_name,
         context->service_worker_version_id(),
         content::WorkerThread::GetCurrentId()));
   }

   void SendAddUnfilteredLazyEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

     dispatcher_->Send(new ExtensionHostMsg_AddLazyServiceWorkerListener(
         context->GetExtensionID(), event_name,
         context->service_worker_scope()));
   }

   void SendRemoveUnfilteredLazyEventListenerIPC(
       ScriptContext* context,
       const std::string& event_name) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

     dispatcher_->Send(new ExtensionHostMsg_RemoveLazyServiceWorkerListener(
         context->GetExtensionID(), event_name,
         context->service_worker_scope()));
   }

   void SendAddFilteredEventListenerIPC(ScriptContext* context,
                                        const std::string& event_name,
                                        const base::DictionaryValue& filter,
                                        bool is_lazy) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
     DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
               context->service_worker_version_id());
     ServiceWorkerIdentifier sw_identifier;
     sw_identifier.scope = context->service_worker_scope();
     sw_identifier.thread_id = content::WorkerThread::GetCurrentId();
     sw_identifier.version_id = context->service_worker_version_id();
     dispatcher_->Send(new ExtensionHostMsg_AddFilteredListener(
         context->GetExtensionID(), event_name, sw_identifier, filter, is_lazy));
   }

   void SendRemoveFilteredEventListenerIPC(ScriptContext* context,
                                           const std::string& event_name,
                                           const base::DictionaryValue& filter,
                                           bool remove_lazy_listener) override {
     DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
     DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
     DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
               context->service_worker_version_id());
     ServiceWorkerIdentifier sw_identifier;
     sw_identifier.scope = context->service_worker_scope();
     sw_identifier.thread_id = content::WorkerThread::GetCurrentId();
     sw_identifier.version_id = context->service_worker_version_id();
     dispatcher_->Send(new ExtensionHostMsg_RemoveFilteredListener(
         context->GetExtensionID(), event_name, sw_identifier, filter,
         remove_lazy_listener));
   }

   void SendOpenMessageChannel(ScriptContext* script_context,
                               const PortId& port_id,
                               const MessageTarget& target,
                               const std::string& channel_name,
                               bool include_tls_channel_id) override {
     DCHECK(!script_context->GetRenderFrame());
     const Extension* extension = script_context->extension();

     switch (target.type) {
       case MessageTarget::EXTENSION: {
         ExtensionMsg_ExternalConnectionInfo info;
         // TODO(crbug.com/925918): Support extension Service Worker to extension
         // messaging.
         DCHECK_EQ(Feature::CONTENT_SCRIPT_CONTEXT,
                   script_context->context_type());
         if (extension && !extension->is_hosted_app()) {
           info.source_endpoint =
               MessagingEndpoint::ForExtension(extension->id());
         }
         info.target_id = *target.extension_id;
         info.source_url = script_context->url();
         dispatcher_->Send(new ExtensionHostMsg_OpenChannelToExtension(
             PortContextForCurrentWorker(), info, channel_name, port_id));
         break;
       }
       case MessageTarget::TAB: {
         DCHECK(extension);
         ExtensionMsg_TabTargetConnectionInfo info;
         info.tab_id = *target.tab_id;
         info.frame_id = *target.frame_id;
         dispatcher_->Send(new ExtensionHostMsg_OpenChannelToTab(
             PortContextForCurrentWorker(), info, extension->id(), channel_name,
             port_id));
         break;
       }
       case MessageTarget::NATIVE_APP:
         NOTIMPLEMENTED() << "https://crbug.com/925918.";
         break;
     }
   }

   void SendOpenMessagePort(int routing_id, const PortId& port_id) override {
     DCHECK_EQ(MSG_ROUTING_NONE, routing_id);
     dispatcher_->Send(new ExtensionHostMsg_OpenMessagePort(
         PortContextForCurrentWorker(), port_id));
   }

   void SendCloseMessagePort(int routing_id,
                             const PortId& port_id,
                             bool close_channel) override {
     DCHECK_EQ(MSG_ROUTING_NONE, routing_id);
     dispatcher_->Send(new ExtensionHostMsg_CloseMessagePort(
         PortContextForCurrentWorker(), port_id, close_channel));
   }

   void SendPostMessageToPort(const PortId& port_id,
                              const Message& message) override {
     dispatcher_->Send(new ExtensionHostMsg_PostMessage(port_id, message));
   }

  private:
   const ExtensionId& GetExtensionId() {
     if (!extension_id_)
       extension_id_ = dispatcher_->GetScriptContext()->extension()->id();
     return *extension_id_;
   }

   PortContext PortContextForCurrentWorker() {
     return PortContext::ForWorker(content::WorkerThread::GetCurrentId(),
                                   service_worker_version_id_, GetExtensionId());
   }

   WorkerThreadDispatcher* const dispatcher_;
   const int64_t service_worker_version_id_;
   base::Optional<ExtensionId> extension_id_;

   // request id -> GUID map for each outstanding requests.
   std::map<int, std::string> request_id_to_guid_;

   DISALLOW_COPY_AND_ASSIGN(WorkerThreadIPCMessageSender);
 };

 }  // namespace

 IPCMessageSender::IPCMessageSender() {}
 IPCMessageSender::~IPCMessageSender() = default;

 // static
 std::unique_ptr<IPCMessageSender>
 IPCMessageSender::CreateMainThreadIPCMessageSender() {
   return std::make_unique<MainThreadIPCMessageSender>();
 }

 // static
 std::unique_ptr<IPCMessageSender>
 IPCMessageSender::CreateWorkerThreadIPCMessageSender(
     WorkerThreadDispatcher* dispatcher,
     int64_t service_worker_version_id) {
   return std::make_unique<WorkerThreadIPCMessageSender>(
       dispatcher, service_worker_version_id);
 }

 }  // namespace extensions
	// 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 "extensions/renderer/ipc_message_sender.h"

	#include <map>

	#include "base/guid.h"
	#include "base/metrics/histogram_macros.h"
	#include "base/optional.h"
	#include "content/public/renderer/render_frame.h"
	#include "content/public/renderer/render_thread.h"
	#include "content/public/renderer/worker_thread.h"
	#include "extensions/common/api/messaging/messaging_endpoint.h"
	#include "extensions/common/constants.h"
	#include "extensions/common/extension_messages.h"
	#include "extensions/common/features/feature.h"
	#include "extensions/renderer/message_target.h"
	#include "extensions/renderer/script_context.h"
	#include "extensions/renderer/worker_thread_dispatcher.h"
	#include "third_party/blink/public/mojom/service_worker/service_worker_registration.mojom.h"

	namespace extensions {

	namespace {

	// These values are logged to UMA. Entries should not be renumbered.
	enum class IncludeTlsChannelIdBehavior {
	// The TLS channel ID was not requested.
	kNotRequested = 0,

	// DEPRECATED: The TLS channel ID was requested, but was not included because
	// the target extension did not allow it.
	// kRequestedButDenied = 1,
	// DEPRECATED: The TLS channel ID was requested, but was not found.
	// kRequestedButNotFound = 2,
	// DEPRECATED: The TLS channel ID was requested, allowed, and included in the
	// response.
	// kRequestedAndIncluded = 3,

	// The TLS channel ID was requested, but was not provided because Channel ID
	// is no longer supported.
	kRequestedButNotSupported = 4,

	kMaxValue = kRequestedButNotSupported,
	};

	void RecordIncludeTlsChannelIdBehavior(bool include_tls_channel_id) {
	auto tls_channel_id_behavior =
	include_tls_channel_id
	? IncludeTlsChannelIdBehavior::kRequestedButNotSupported
	: IncludeTlsChannelIdBehavior::kNotRequested;
	UMA_HISTOGRAM_ENUMERATION("Extensions.Messaging.IncludeChannelIdBehavior",
	tls_channel_id_behavior);
	}

	class MainThreadIPCMessageSender : public IPCMessageSender {
	public:
	MainThreadIPCMessageSender() : render_thread_(content::RenderThread::Get()) {}
	~MainThreadIPCMessageSender() override {}

	void SendRequestIPC(ScriptContext* context,
	std::unique_ptr<ExtensionHostMsg_Request_Params> params,
	binding::RequestThread thread) override {
	content::RenderFrame* frame = context->GetRenderFrame();
	if (!frame)
	return;

	switch (thread) {
	case binding::RequestThread::UI:
	frame->Send(
	new ExtensionHostMsg_Request(frame->GetRoutingID(), *params));
	break;
	case binding::RequestThread::IO:
	frame->Send(new ExtensionHostMsg_RequestForIOThread(
	frame->GetRoutingID(), *params));
	break;
	}
	}

	void SendOnRequestResponseReceivedIPC(int request_id) override {}

	void SendAddUnfilteredEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_AddListener(
	context->GetExtensionID(), context->url(), event_name,
	blink::mojom::kInvalidServiceWorkerVersionId, kMainThreadId));
	}

	void SendRemoveUnfilteredEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_RemoveListener(
	context->GetExtensionID(), context->url(), event_name,
	blink::mojom::kInvalidServiceWorkerVersionId, kMainThreadId));
	}

	void SendAddUnfilteredLazyEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_AddLazyListener(
	context->GetExtensionID(), event_name));
	}

	void SendRemoveUnfilteredLazyEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_RemoveLazyListener(
	context->GetExtensionID(), event_name));
	}

	void SendAddFilteredEventListenerIPC(ScriptContext* context,
	const std::string& event_name,
	const base::DictionaryValue& filter,
	bool is_lazy) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_AddFilteredListener(
	context->GetExtensionID(), event_name, base::nullopt, filter, is_lazy));
	}

	void SendRemoveFilteredEventListenerIPC(ScriptContext* context,
	const std::string& event_name,
	const base::DictionaryValue& filter,
	bool remove_lazy_listener) override {
	DCHECK_NE(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(kMainThreadId, content::WorkerThread::GetCurrentId());

	render_thread_->Send(new ExtensionHostMsg_RemoveFilteredListener(
	context->GetExtensionID(), event_name, base::nullopt, filter,
	remove_lazy_listener));
	}

	void SendOpenMessageChannel(ScriptContext* script_context,
	const PortId& port_id,
	const MessageTarget& target,
	const std::string& channel_name,
	bool include_tls_channel_id) override {
	RecordIncludeTlsChannelIdBehavior(include_tls_channel_id);
	content::RenderFrame* render_frame = script_context->GetRenderFrame();
	DCHECK(render_frame);
	PortContext frame_context =
	PortContext::ForFrame(render_frame->GetRoutingID());
	const Extension* extension = script_context->extension();

	switch (target.type) {
	case MessageTarget::EXTENSION: {
	ExtensionMsg_ExternalConnectionInfo info;
	if (extension && !extension->is_hosted_app()) {
	info.source_endpoint =
	script_context->context_type() == Feature::CONTENT_SCRIPT_CONTEXT
	? MessagingEndpoint::ForContentScript(extension->id())
	: MessagingEndpoint::ForExtension(extension->id());
	} else {
	info.source_endpoint = MessagingEndpoint::ForWebPage();
	}
	info.target_id = *target.extension_id;
	info.source_url = script_context->url();

	render_thread_->Send(new ExtensionHostMsg_OpenChannelToExtension(
	frame_context, info, channel_name, port_id));
	break;
	}
	case MessageTarget::TAB: {
	DCHECK(extension);
	DCHECK_NE(script_context->context_type(),
	Feature::CONTENT_SCRIPT_CONTEXT);
	ExtensionMsg_TabTargetConnectionInfo info;
	info.tab_id = *target.tab_id;
	info.frame_id = *target.frame_id;
	render_frame->Send(new ExtensionHostMsg_OpenChannelToTab(
	frame_context, info, extension->id(), channel_name, port_id));
	break;
	}
	case MessageTarget::NATIVE_APP:
	render_frame->Send(new ExtensionHostMsg_OpenChannelToNativeApp(
	frame_context, *target.native_application_name, port_id));
	break;
	}
	}

	void SendOpenMessagePort(int routing_id, const PortId& port_id) override {
	render_thread_->Send(new ExtensionHostMsg_OpenMessagePort(
	PortContext::ForFrame(routing_id), port_id));
	}

	void SendCloseMessagePort(int routing_id,
	const PortId& port_id,
	bool close_channel) override {
	render_thread_->Send(new ExtensionHostMsg_CloseMessagePort(
	PortContext::ForFrame(routing_id), port_id, close_channel));
	}

	void SendPostMessageToPort(const PortId& port_id,
	const Message& message) override {
	render_thread_->Send(new ExtensionHostMsg_PostMessage(port_id, message));
	}

	private:
	content::RenderThread* const render_thread_;

	DISALLOW_COPY_AND_ASSIGN(MainThreadIPCMessageSender);
	};

	class WorkerThreadIPCMessageSender : public IPCMessageSender {
	public:
	WorkerThreadIPCMessageSender(WorkerThreadDispatcher* dispatcher,
	int64_t service_worker_version_id)
	: dispatcher_(dispatcher),
	service_worker_version_id_(service_worker_version_id) {}
	~WorkerThreadIPCMessageSender() override {}

	void SendRequestIPC(ScriptContext* context,
	std::unique_ptr<ExtensionHostMsg_Request_Params> params,
	binding::RequestThread thread) override {
	DCHECK(!context->GetRenderFrame());
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_EQ(binding::RequestThread::UI, thread);
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

	int worker_thread_id = content::WorkerThread::GetCurrentId();
	params->worker_thread_id = worker_thread_id;
	params->service_worker_version_id = service_worker_version_id_;

	std::string guid = base::GenerateGUID();
	request_id_to_guid_[params->request_id] = guid;

	// Keeps the worker alive during extension function call. Balanced in
	// HandleWorkerResponse().
	dispatcher_->Send(new ExtensionHostMsg_IncrementServiceWorkerActivity(
	service_worker_version_id_, guid));

	dispatcher_->Send(new ExtensionHostMsg_RequestWorker(*params));
	}

	void SendOnRequestResponseReceivedIPC(int request_id) override {
	auto iter = request_id_to_guid_.find(request_id);
	DCHECK(iter != request_id_to_guid_.end());
	dispatcher_->Send(new ExtensionHostMsg_DecrementServiceWorkerActivity(
	service_worker_version_id_, iter->second));
	request_id_to_guid_.erase(iter);
	}

	void SendAddUnfilteredEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
	DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
	context->service_worker_version_id());

	dispatcher_->Send(new ExtensionHostMsg_AddListener(
	context->GetExtensionID(), context->service_worker_scope(), event_name,
	context->service_worker_version_id(),
	content::WorkerThread::GetCurrentId()));
	}

	void SendRemoveUnfilteredEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
	DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
	context->service_worker_version_id());

	dispatcher_->Send(new ExtensionHostMsg_RemoveListener(
	context->GetExtensionID(), context->service_worker_scope(), event_name,
	context->service_worker_version_id(),
	content::WorkerThread::GetCurrentId()));
	}

	void SendAddUnfilteredLazyEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

	dispatcher_->Send(new ExtensionHostMsg_AddLazyServiceWorkerListener(
	context->GetExtensionID(), event_name,
	context->service_worker_scope()));
	}

	void SendRemoveUnfilteredLazyEventListenerIPC(
	ScriptContext* context,
	const std::string& event_name) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());

	dispatcher_->Send(new ExtensionHostMsg_RemoveLazyServiceWorkerListener(
	context->GetExtensionID(), event_name,
	context->service_worker_scope()));
	}

	void SendAddFilteredEventListenerIPC(ScriptContext* context,
	const std::string& event_name,
	const base::DictionaryValue& filter,
	bool is_lazy) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
	DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
	context->service_worker_version_id());
	ServiceWorkerIdentifier sw_identifier;
	sw_identifier.scope = context->service_worker_scope();
	sw_identifier.thread_id = content::WorkerThread::GetCurrentId();
	sw_identifier.version_id = context->service_worker_version_id();
	dispatcher_->Send(new ExtensionHostMsg_AddFilteredListener(
	context->GetExtensionID(), event_name, sw_identifier, filter, is_lazy));
	}

	void SendRemoveFilteredEventListenerIPC(ScriptContext* context,
	const std::string& event_name,
	const base::DictionaryValue& filter,
	bool remove_lazy_listener) override {
	DCHECK_EQ(Feature::SERVICE_WORKER_CONTEXT, context->context_type());
	DCHECK_NE(kMainThreadId, content::WorkerThread::GetCurrentId());
	DCHECK_NE(blink::mojom::kInvalidServiceWorkerVersionId,
	context->service_worker_version_id());
	ServiceWorkerIdentifier sw_identifier;
	sw_identifier.scope = context->service_worker_scope();
	sw_identifier.thread_id = content::WorkerThread::GetCurrentId();
	sw_identifier.version_id = context->service_worker_version_id();
	dispatcher_->Send(new ExtensionHostMsg_RemoveFilteredListener(
	context->GetExtensionID(), event_name, sw_identifier, filter,
	remove_lazy_listener));
	}

	void SendOpenMessageChannel(ScriptContext* script_context,
	const PortId& port_id,
	const MessageTarget& target,
	const std::string& channel_name,
	bool include_tls_channel_id) override {
	DCHECK(!script_context->GetRenderFrame());
	const Extension* extension = script_context->extension();

	switch (target.type) {
	case MessageTarget::EXTENSION: {
	ExtensionMsg_ExternalConnectionInfo info;
	// TODO(crbug.com/925918): Support extension Service Worker to extension
	// messaging.
	DCHECK_EQ(Feature::CONTENT_SCRIPT_CONTEXT,
	script_context->context_type());
	if (extension && !extension->is_hosted_app()) {
	info.source_endpoint =
	MessagingEndpoint::ForExtension(extension->id());
	}
	info.target_id = *target.extension_id;
	info.source_url = script_context->url();
	dispatcher_->Send(new ExtensionHostMsg_OpenChannelToExtension(
	PortContextForCurrentWorker(), info, channel_name, port_id));
	break;
	}
	case MessageTarget::TAB: {
	DCHECK(extension);
	ExtensionMsg_TabTargetConnectionInfo info;
	info.tab_id = *target.tab_id;
	info.frame_id = *target.frame_id;
	dispatcher_->Send(new ExtensionHostMsg_OpenChannelToTab(
	PortContextForCurrentWorker(), info, extension->id(), channel_name,
	port_id));
	break;
	}
	case MessageTarget::NATIVE_APP:
	NOTIMPLEMENTED() << "https://crbug.com/925918.";
	break;
	}
	}

	void SendOpenMessagePort(int routing_id, const PortId& port_id) override {
	DCHECK_EQ(MSG_ROUTING_NONE, routing_id);
	dispatcher_->Send(new ExtensionHostMsg_OpenMessagePort(
	PortContextForCurrentWorker(), port_id));
	}

	void SendCloseMessagePort(int routing_id,
	const PortId& port_id,
	bool close_channel) override {
	DCHECK_EQ(MSG_ROUTING_NONE, routing_id);
	dispatcher_->Send(new ExtensionHostMsg_CloseMessagePort(
	PortContextForCurrentWorker(), port_id, close_channel));
	}

	void SendPostMessageToPort(const PortId& port_id,
	const Message& message) override {
	dispatcher_->Send(new ExtensionHostMsg_PostMessage(port_id, message));
	}

	private:
	const ExtensionId& GetExtensionId() {
	if (!extension_id_)
	extension_id_ = dispatcher_->GetScriptContext()->extension()->id();
	return *extension_id_;
	}

	PortContext PortContextForCurrentWorker() {
	return PortContext::ForWorker(content::WorkerThread::GetCurrentId(),
	service_worker_version_id_, GetExtensionId());
	}

	WorkerThreadDispatcher* const dispatcher_;
	const int64_t service_worker_version_id_;
	base::Optional<ExtensionId> extension_id_;

	// request id -> GUID map for each outstanding requests.
	std::map<int, std::string> request_id_to_guid_;

	DISALLOW_COPY_AND_ASSIGN(WorkerThreadIPCMessageSender);
	};

	} // namespace

	IPCMessageSender::IPCMessageSender() {}
	IPCMessageSender::~IPCMessageSender() = default;

	// static
	std::unique_ptr<IPCMessageSender>
	IPCMessageSender::CreateMainThreadIPCMessageSender() {
	return std::make_unique<MainThreadIPCMessageSender>();
	}

	// static
	std::unique_ptr<IPCMessageSender>
	IPCMessageSender::CreateWorkerThreadIPCMessageSender(
	WorkerThreadDispatcher* dispatcher,
	int64_t service_worker_version_id) {
	return std::make_unique<WorkerThreadIPCMessageSender>(
	dispatcher, service_worker_version_id);
	}

	} // namespace extensions