// Copyright (c) 2012 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/child/child_thread_impl.h" #include #include #include #include "base/base_switches.h" #include "base/command_line.h" #include "base/debug/leak_annotations.h" #include "base/debug/profiler.h" #include "base/lazy_instance.h" #include "base/location.h" #include "base/logging.h" #include "base/macros.h" #include "base/message_loop/timer_slack.h" #include "base/metrics/field_trial.h" #include "base/process/process.h" #include "base/process/process_handle.h" #include "base/single_thread_task_runner.h" #include "base/strings/string_number_conversions.h" #include "base/strings/string_util.h" #include "base/synchronization/condition_variable.h" #include "base/synchronization/lock.h" #include "base/thread_task_runner_handle.h" #include "base/threading/thread_local.h" #include "base/tracked_objects.h" #include "build/build_config.h" #include "components/tracing/child_trace_message_filter.h" #include "content/child/child_discardable_shared_memory_manager.h" #include "content/child/child_gpu_memory_buffer_manager.h" #include "content/child/child_histogram_message_filter.h" #include "content/child/child_process.h" #include "content/child/child_resource_message_filter.h" #include "content/child/child_shared_bitmap_manager.h" #include "content/child/fileapi/file_system_dispatcher.h" #include "content/child/fileapi/webfilesystem_impl.h" #include "content/child/geofencing/geofencing_message_filter.h" #include "content/child/memory/child_memory_message_filter.h" #include "content/child/mojo/mojo_application.h" #include "content/child/notifications/notification_dispatcher.h" #include "content/child/power_monitor_broadcast_source.h" #include "content/child/push_messaging/push_dispatcher.h" #include "content/child/quota_dispatcher.h" #include "content/child/quota_message_filter.h" #include "content/child/resource_dispatcher.h" #include "content/child/service_worker/service_worker_message_filter.h" #include "content/child/thread_safe_sender.h" #include "content/child/websocket_dispatcher.h" #include "content/common/child_process_messages.h" #include "content/common/in_process_child_thread_params.h" #include "content/common/mojo/mojo_messages.h" #include "content/public/common/content_switches.h" #include "ipc/attachment_broker.h" #include "ipc/attachment_broker_unprivileged.h" #include "ipc/ipc_logging.h" #include "ipc/ipc_platform_file.h" #include "ipc/ipc_switches.h" #include "ipc/ipc_sync_channel.h" #include "ipc/ipc_sync_message_filter.h" #include "ipc/mojo/ipc_channel_mojo.h" #include "third_party/mojo/src/mojo/edk/embedder/embedder.h" #if defined(TCMALLOC_TRACE_MEMORY_SUPPORTED) #include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h" #endif #if defined(USE_OZONE) #include "ui/ozone/public/client_native_pixmap_factory.h" #endif #if defined(MOJO_SHELL_CLIENT) #include "content/common/mojo/mojo_shell_connection_impl.h" #endif using tracked_objects::ThreadData; namespace content { namespace { // How long to wait for a connection to the browser process before giving up. const int kConnectionTimeoutS = 15; base::LazyInstance > g_lazy_tls = LAZY_INSTANCE_INITIALIZER; // This isn't needed on Windows because there the sandbox's job object // terminates child processes automatically. For unsandboxed processes (i.e. // plugins), PluginThread has EnsureTerminateMessageFilter. #if defined(OS_POSIX) #if defined(ADDRESS_SANITIZER) || defined(LEAK_SANITIZER) || \ defined(MEMORY_SANITIZER) || defined(THREAD_SANITIZER) || \ defined(UNDEFINED_SANITIZER) // A thread delegate that waits for |duration| and then exits the process with // _exit(0). class WaitAndExitDelegate : public base::PlatformThread::Delegate { public: explicit WaitAndExitDelegate(base::TimeDelta duration) : duration_(duration) {} void ThreadMain() override { base::PlatformThread::Sleep(duration_); _exit(0); } private: const base::TimeDelta duration_; DISALLOW_COPY_AND_ASSIGN(WaitAndExitDelegate); }; bool CreateWaitAndExitThread(base::TimeDelta duration) { scoped_ptr delegate(new WaitAndExitDelegate(duration)); const bool thread_created = base::PlatformThread::CreateNonJoinable(0, delegate.get()); if (!thread_created) return false; // A non joinable thread has been created. The thread will either terminate // the process or will be terminated by the process. Therefore, keep the // delegate object alive for the lifetime of the process. WaitAndExitDelegate* leaking_delegate = delegate.release(); ANNOTATE_LEAKING_OBJECT_PTR(leaking_delegate); ignore_result(leaking_delegate); return true; } #endif class SuicideOnChannelErrorFilter : public IPC::MessageFilter { public: // IPC::MessageFilter void OnChannelError() override { // For renderer/worker processes: // On POSIX, at least, one can install an unload handler which loops // forever and leave behind a renderer process which eats 100% CPU forever. // // This is because the terminate signals (FrameMsg_BeforeUnload and the // error from the IPC sender) are routed to the main message loop but never // processed (because that message loop is stuck in V8). // // One could make the browser SIGKILL the renderers, but that leaves open a // large window where a browser failure (or a user, manually terminating // the browser because "it's stuck") will leave behind a process eating all // the CPU. // // So, we install a filter on the sender so that we can process this event // here and kill the process. base::debug::StopProfiling(); #if defined(ADDRESS_SANITIZER) || defined(LEAK_SANITIZER) || \ defined(MEMORY_SANITIZER) || defined(THREAD_SANITIZER) || \ defined(UNDEFINED_SANITIZER) // Some sanitizer tools rely on exit handlers (e.g. to run leak detection, // or dump code coverage data to disk). Instead of exiting the process // immediately, we give it 60 seconds to run exit handlers. CHECK(CreateWaitAndExitThread(base::TimeDelta::FromSeconds(60))); #if defined(LEAK_SANITIZER) // Invoke LeakSanitizer early to avoid detecting shutdown-only leaks. If // leaks are found, the process will exit here. __lsan_do_leak_check(); #endif #else _exit(0); #endif } protected: ~SuicideOnChannelErrorFilter() override {} }; #endif // OS(POSIX) #if defined(USE_OZONE) class ClientNativePixmapFactoryFilter : public IPC::MessageFilter { public: // Overridden from IPC::MessageFilter: bool OnMessageReceived(const IPC::Message& message) override { bool handled = true; IPC_BEGIN_MESSAGE_MAP(ClientNativePixmapFactoryFilter, message) IPC_MESSAGE_HANDLER(ChildProcessMsg_InitializeClientNativePixmapFactory, OnInitializeClientNativePixmapFactory) IPC_MESSAGE_UNHANDLED(handled = false) IPC_END_MESSAGE_MAP() return handled; } protected: ~ClientNativePixmapFactoryFilter() override {} void OnInitializeClientNativePixmapFactory( const base::FileDescriptor& device_fd) { ui::ClientNativePixmapFactory::GetInstance()->Initialize( base::ScopedFD(device_fd.fd)); } }; #endif #if defined(OS_ANDROID) // A class that allows for triggering a clean shutdown from another // thread through draining the main thread's msg loop. class QuitClosure { public: QuitClosure(); ~QuitClosure(); void BindToMainThread(); void PostQuitFromNonMainThread(); private: static void PostClosure( const scoped_refptr& task_runner, base::Closure closure); base::Lock lock_; base::ConditionVariable cond_var_; base::Closure closure_; }; QuitClosure::QuitClosure() : cond_var_(&lock_) { } QuitClosure::~QuitClosure() { } void QuitClosure::PostClosure( const scoped_refptr& task_runner, base::Closure closure) { task_runner->PostTask(FROM_HERE, closure); } void QuitClosure::BindToMainThread() { base::AutoLock lock(lock_); scoped_refptr task_runner( base::ThreadTaskRunnerHandle::Get()); base::Closure quit_closure = base::MessageLoop::current()->QuitWhenIdleClosure(); closure_ = base::Bind(&QuitClosure::PostClosure, task_runner, quit_closure); cond_var_.Signal(); } void QuitClosure::PostQuitFromNonMainThread() { base::AutoLock lock(lock_); while (closure_.is_null()) cond_var_.Wait(); closure_.Run(); } base::LazyInstance g_quit_closure = LAZY_INSTANCE_INITIALIZER; #endif } // namespace ChildThread* ChildThread::Get() { return ChildThreadImpl::current(); } ChildThreadImpl::Options::Options() : channel_name(base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII( switches::kProcessChannelID)), use_mojo_channel(false) { } ChildThreadImpl::Options::~Options() { } ChildThreadImpl::Options::Builder::Builder() { } ChildThreadImpl::Options::Builder& ChildThreadImpl::Options::Builder::InBrowserProcess( const InProcessChildThreadParams& params) { options_.browser_process_io_runner = params.io_runner(); options_.channel_name = params.channel_name(); return *this; } ChildThreadImpl::Options::Builder& ChildThreadImpl::Options::Builder::UseMojoChannel(bool use_mojo_channel) { options_.use_mojo_channel = use_mojo_channel; return *this; } ChildThreadImpl::Options::Builder& ChildThreadImpl::Options::Builder::WithChannelName( const std::string& channel_name) { options_.channel_name = channel_name; return *this; } ChildThreadImpl::Options::Builder& ChildThreadImpl::Options::Builder::AddStartupFilter( IPC::MessageFilter* filter) { options_.startup_filters.push_back(filter); return *this; } ChildThreadImpl::Options ChildThreadImpl::Options::Builder::Build() { return options_; } ChildThreadImpl::ChildThreadMessageRouter::ChildThreadMessageRouter( IPC::Sender* sender) : sender_(sender) {} bool ChildThreadImpl::ChildThreadMessageRouter::Send(IPC::Message* msg) { return sender_->Send(msg); } bool ChildThreadImpl::ChildThreadMessageRouter::RouteMessage( const IPC::Message& msg) { bool handled = MessageRouter::RouteMessage(msg); #if defined(OS_ANDROID) if (!handled && msg.is_sync()) { IPC::Message* reply = IPC::SyncMessage::GenerateReply(&msg); reply->set_reply_error(); Send(reply); } #endif return handled; } ChildThreadImpl::ChildThreadImpl() : router_(this), channel_connected_factory_(this) { Init(Options::Builder().Build()); } ChildThreadImpl::ChildThreadImpl(const Options& options) : router_(this), browser_process_io_runner_(options.browser_process_io_runner), channel_connected_factory_(this) { Init(options); } scoped_refptr ChildThreadImpl::GetIOTaskRunner() { if (IsInBrowserProcess()) return browser_process_io_runner_; return ChildProcess::current()->io_task_runner(); } void ChildThreadImpl::ConnectChannel(bool use_mojo_channel) { bool create_pipe_now = true; if (use_mojo_channel) { VLOG(1) << "Mojo is enabled on child"; scoped_refptr io_task_runner = GetIOTaskRunner(); DCHECK(io_task_runner); channel_->Init( IPC::ChannelMojo::CreateClientFactory(io_task_runner, channel_name_), create_pipe_now); return; } VLOG(1) << "Mojo is disabled on child"; channel_->Init(channel_name_, IPC::Channel::MODE_CLIENT, create_pipe_now); } void ChildThreadImpl::Init(const Options& options) { channel_name_ = options.channel_name; g_lazy_tls.Pointer()->Set(this); on_channel_error_called_ = false; message_loop_ = base::MessageLoop::current(); #ifdef IPC_MESSAGE_LOG_ENABLED // We must make sure to instantiate the IPC Logger *before* we create the // channel, otherwise we can get a callback on the IO thread which creates // the logger, and the logger does not like being created on the IO thread. IPC::Logging::GetInstance(); #endif #if USE_ATTACHMENT_BROKER // The only reason a global would already exist is if the thread is being run // in the browser process because of a command line switch. if (!IPC::AttachmentBroker::GetGlobal()) { attachment_broker_.reset( IPC::AttachmentBrokerUnprivileged::CreateBroker().release()); } #endif channel_ = IPC::SyncChannel::Create(this, ChildProcess::current()->io_task_runner(), ChildProcess::current()->GetShutDownEvent()); #ifdef IPC_MESSAGE_LOG_ENABLED if (!IsInBrowserProcess()) IPC::Logging::GetInstance()->SetIPCSender(this); #endif mojo_ipc_support_.reset(new IPC::ScopedIPCSupport(GetIOTaskRunner())); mojo_application_.reset(new MojoApplication(GetIOTaskRunner())); sync_message_filter_ = channel_->CreateSyncMessageFilter(); thread_safe_sender_ = new ThreadSafeSender( message_loop_->task_runner(), sync_message_filter_.get()); resource_dispatcher_.reset(new ResourceDispatcher( this, message_loop()->task_runner())); websocket_dispatcher_.reset(new WebSocketDispatcher); file_system_dispatcher_.reset(new FileSystemDispatcher()); histogram_message_filter_ = new ChildHistogramMessageFilter(); resource_message_filter_ = new ChildResourceMessageFilter(resource_dispatcher()); service_worker_message_filter_ = new ServiceWorkerMessageFilter(thread_safe_sender_.get()); quota_message_filter_ = new QuotaMessageFilter(thread_safe_sender_.get()); quota_dispatcher_.reset(new QuotaDispatcher(thread_safe_sender_.get(), quota_message_filter_.get())); geofencing_message_filter_ = new GeofencingMessageFilter(thread_safe_sender_.get()); notification_dispatcher_ = new NotificationDispatcher(thread_safe_sender_.get()); push_dispatcher_ = new PushDispatcher(thread_safe_sender_.get()); channel_->AddFilter(histogram_message_filter_.get()); channel_->AddFilter(resource_message_filter_.get()); channel_->AddFilter(quota_message_filter_->GetFilter()); channel_->AddFilter(notification_dispatcher_->GetFilter()); channel_->AddFilter(push_dispatcher_->GetFilter()); channel_->AddFilter(service_worker_message_filter_->GetFilter()); channel_->AddFilter(geofencing_message_filter_->GetFilter()); if (!IsInBrowserProcess()) { // In single process mode, browser-side tracing and memory will cover the // whole process including renderers. channel_->AddFilter(new tracing::ChildTraceMessageFilter( ChildProcess::current()->io_task_runner())); channel_->AddFilter(new ChildMemoryMessageFilter()); } // In single process mode we may already have a power monitor if (!base::PowerMonitor::Get()) { scoped_ptr power_monitor_source( new PowerMonitorBroadcastSource()); channel_->AddFilter(power_monitor_source->GetMessageFilter()); power_monitor_.reset( new base::PowerMonitor(std::move(power_monitor_source))); } #if defined(OS_POSIX) // Check that --process-type is specified so we don't do this in unit tests // and single-process mode. if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kProcessType)) channel_->AddFilter(new SuicideOnChannelErrorFilter()); #endif #if defined(USE_OZONE) channel_->AddFilter(new ClientNativePixmapFactoryFilter()); #endif // Add filters passed here via options. for (auto startup_filter : options.startup_filters) { channel_->AddFilter(startup_filter); } ConnectChannel(options.use_mojo_channel); if (attachment_broker_) attachment_broker_->DesignateBrokerCommunicationChannel(channel_.get()); int connection_timeout = kConnectionTimeoutS; std::string connection_override = base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII( switches::kIPCConnectionTimeout); if (!connection_override.empty()) { int temp; if (base::StringToInt(connection_override, &temp)) connection_timeout = temp; } message_loop_->task_runner()->PostDelayedTask( FROM_HERE, base::Bind(&ChildThreadImpl::EnsureConnected, channel_connected_factory_.GetWeakPtr()), base::TimeDelta::FromSeconds(connection_timeout)); #if defined(OS_ANDROID) g_quit_closure.Get().BindToMainThread(); #endif shared_bitmap_manager_.reset( new ChildSharedBitmapManager(thread_safe_sender())); gpu_memory_buffer_manager_.reset( new ChildGpuMemoryBufferManager(thread_safe_sender())); discardable_shared_memory_manager_.reset( new ChildDiscardableSharedMemoryManager(thread_safe_sender())); } ChildThreadImpl::~ChildThreadImpl() { #ifdef IPC_MESSAGE_LOG_ENABLED IPC::Logging::GetInstance()->SetIPCSender(NULL); #endif channel_->RemoveFilter(histogram_message_filter_.get()); channel_->RemoveFilter(sync_message_filter_.get()); // The ChannelProxy object caches a pointer to the IPC thread, so need to // reset it as it's not guaranteed to outlive this object. // NOTE: this also has the side-effect of not closing the main IPC channel to // the browser process. This is needed because this is the signal that the // browser uses to know that this process has died, so we need it to be alive // until this process is shut down, and the OS closes the handle // automatically. We used to watch the object handle on Windows to do this, // but it wasn't possible to do so on POSIX. channel_->ClearIPCTaskRunner(); g_lazy_tls.Pointer()->Set(NULL); } void ChildThreadImpl::Shutdown() { // Delete objects that hold references to blink so derived classes can // safely shutdown blink in their Shutdown implementation. file_system_dispatcher_.reset(); quota_dispatcher_.reset(); WebFileSystemImpl::DeleteThreadSpecificInstance(); // ChildDiscardableSharedMemoryManager has to be destroyed while // |thread_safe_sender_| and |message_loop_| are still valid. discardable_shared_memory_manager_.reset(); } void ChildThreadImpl::OnChannelConnected(int32_t peer_pid) { channel_connected_factory_.InvalidateWeakPtrs(); } void ChildThreadImpl::OnChannelError() { on_channel_error_called_ = true; base::MessageLoop::current()->QuitWhenIdle(); } bool ChildThreadImpl::Send(IPC::Message* msg) { DCHECK(base::MessageLoop::current() == message_loop()); if (!channel_) { delete msg; return false; } return channel_->Send(msg); } #if defined(OS_WIN) void ChildThreadImpl::PreCacheFont(const LOGFONT& log_font) { Send(new ChildProcessHostMsg_PreCacheFont(log_font)); } void ChildThreadImpl::ReleaseCachedFonts() { Send(new ChildProcessHostMsg_ReleaseCachedFonts()); } #endif MessageRouter* ChildThreadImpl::GetRouter() { DCHECK(base::MessageLoop::current() == message_loop()); return &router_; } scoped_ptr ChildThreadImpl::AllocateSharedMemory( size_t buf_size) { DCHECK(base::MessageLoop::current() == message_loop()); return AllocateSharedMemory(buf_size, this); } // static scoped_ptr ChildThreadImpl::AllocateSharedMemory( size_t buf_size, IPC::Sender* sender) { scoped_ptr shared_buf; #if defined(OS_WIN) shared_buf.reset(new base::SharedMemory); if (!shared_buf->CreateAnonymous(buf_size)) { NOTREACHED(); return nullptr; } #else // On POSIX, we need to ask the browser to create the shared memory for us, // since this is blocked by the sandbox. base::SharedMemoryHandle shared_mem_handle; if (sender->Send(new ChildProcessHostMsg_SyncAllocateSharedMemory( buf_size, &shared_mem_handle))) { if (base::SharedMemory::IsHandleValid(shared_mem_handle)) { shared_buf.reset(new base::SharedMemory(shared_mem_handle, false)); } else { NOTREACHED() << "Browser failed to allocate shared memory"; return nullptr; } } else { // Send is allowed to fail during shutdown. Return null in this case. return nullptr; } #endif return shared_buf; } bool ChildThreadImpl::OnMessageReceived(const IPC::Message& msg) { if (mojo_application_->OnMessageReceived(msg)) return true; // Resource responses are sent to the resource dispatcher. if (resource_dispatcher_->OnMessageReceived(msg)) return true; if (websocket_dispatcher_->OnMessageReceived(msg)) return true; if (file_system_dispatcher_->OnMessageReceived(msg)) return true; bool handled = true; IPC_BEGIN_MESSAGE_MAP(ChildThreadImpl, msg) IPC_MESSAGE_HANDLER(ChildProcessMsg_Shutdown, OnShutdown) #if defined(IPC_MESSAGE_LOG_ENABLED) IPC_MESSAGE_HANDLER(ChildProcessMsg_SetIPCLoggingEnabled, OnSetIPCLoggingEnabled) #endif IPC_MESSAGE_HANDLER(ChildProcessMsg_SetProfilerStatus, OnSetProfilerStatus) IPC_MESSAGE_HANDLER(ChildProcessMsg_GetChildProfilerData, OnGetChildProfilerData) IPC_MESSAGE_HANDLER(ChildProcessMsg_ProfilingPhaseCompleted, OnProfilingPhaseCompleted) IPC_MESSAGE_HANDLER(ChildProcessMsg_SetProcessBackgrounded, OnProcessBackgrounded) IPC_MESSAGE_HANDLER(MojoMsg_BindExternalMojoShellHandle, OnBindExternalMojoShellHandle) IPC_MESSAGE_HANDLER(ChildProcessMsg_SetMojoParentPipeHandle, OnSetMojoParentPipeHandle) IPC_MESSAGE_UNHANDLED(handled = false) IPC_END_MESSAGE_MAP() if (handled) return true; if (msg.routing_id() == MSG_ROUTING_CONTROL) return OnControlMessageReceived(msg); return router_.OnMessageReceived(msg); } bool ChildThreadImpl::OnControlMessageReceived(const IPC::Message& msg) { return false; } void ChildThreadImpl::OnProcessBackgrounded(bool backgrounded) { // Set timer slack to maximum on main thread when in background. base::TimerSlack timer_slack = base::TIMER_SLACK_NONE; if (backgrounded) timer_slack = base::TIMER_SLACK_MAXIMUM; base::MessageLoop::current()->SetTimerSlack(timer_slack); } void ChildThreadImpl::OnShutdown() { base::MessageLoop::current()->QuitWhenIdle(); } #if defined(IPC_MESSAGE_LOG_ENABLED) void ChildThreadImpl::OnSetIPCLoggingEnabled(bool enable) { if (enable) IPC::Logging::GetInstance()->Enable(); else IPC::Logging::GetInstance()->Disable(); } #endif // IPC_MESSAGE_LOG_ENABLED void ChildThreadImpl::OnSetProfilerStatus(ThreadData::Status status) { ThreadData::InitializeAndSetTrackingStatus(status); } void ChildThreadImpl::OnGetChildProfilerData(int sequence_number, int current_profiling_phase) { tracked_objects::ProcessDataSnapshot process_data; ThreadData::Snapshot(current_profiling_phase, &process_data); Send( new ChildProcessHostMsg_ChildProfilerData(sequence_number, process_data)); } void ChildThreadImpl::OnProfilingPhaseCompleted(int profiling_phase) { ThreadData::OnProfilingPhaseCompleted(profiling_phase); } void ChildThreadImpl::OnBindExternalMojoShellHandle( const IPC::PlatformFileForTransit& file) { #if defined(MOJO_SHELL_CLIENT) #if defined(OS_POSIX) base::PlatformFile handle = file.fd; #elif defined(OS_WIN) base::PlatformFile handle = file; #endif mojo::ScopedMessagePipeHandle message_pipe = mojo_shell_channel_init_.Init(handle, GetIOTaskRunner()); DCHECK(message_pipe.is_valid()); MojoShellConnectionImpl::Get()->BindToMessagePipe(std::move(message_pipe)); #endif // defined(MOJO_SHELL_CLIENT) } void ChildThreadImpl::OnSetMojoParentPipeHandle( const IPC::PlatformFileForTransit& file) { mojo::embedder::SetParentPipeHandle( mojo::embedder::ScopedPlatformHandle(mojo::embedder::PlatformHandle( IPC::PlatformFileForTransitToPlatformFile(file)))); } ChildThreadImpl* ChildThreadImpl::current() { return g_lazy_tls.Pointer()->Get(); } #if defined(OS_ANDROID) // The method must NOT be called on the child thread itself. // It may block the child thread if so. void ChildThreadImpl::ShutdownThread() { DCHECK(!ChildThreadImpl::current()) << "this method should NOT be called from child thread itself"; g_quit_closure.Get().PostQuitFromNonMainThread(); } #endif void ChildThreadImpl::OnProcessFinalRelease() { if (on_channel_error_called_) return; // The child process shutdown sequence is a request response based mechanism, // where we send out an initial feeler request to the child process host // instance in the browser to verify if it's ok to shutdown the child process. // The browser then sends back a response if it's ok to shutdown. This avoids // race conditions if the process refcount is 0 but there's an IPC message // inflight that would addref it. Send(new ChildProcessHostMsg_ShutdownRequest); } void ChildThreadImpl::EnsureConnected() { VLOG(0) << "ChildThreadImpl::EnsureConnected()"; base::Process::Current().Terminate(0, false); } bool ChildThreadImpl::IsInBrowserProcess() const { return browser_process_io_runner_; } } // namespace content