Unifying ChildProcessLauncher across platforms.

content/browser/child_process_launcher.cc

Index: content/browser/child_process_launcher.cc
diff --git a/content/browser/child_process_launcher.cc b/content/browser/child_process_launcher.cc
index 51f5696d31456265c29fc75933f95628aada588b..434fae7b2315c375647810bec18fdf93bedad9b3 100644
--- a/content/browser/child_process_launcher.cc
+++ b/content/browser/child_process_launcher.cc
@@ -4,75 +4,23 @@
 
 #include "content/browser/child_process_launcher.h"
 
-#include <memory>
-#include <utility>
-
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/i18n/icu_util.h"
 #include "base/logging.h"
-#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/process/launch.h"
-#include "base/process/process.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/thread.h"
 #include "build/build_config.h"
-#include "content/public/browser/content_browser_client.h"
-#include "content/public/common/content_descriptors.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
-#include "mojo/edk/embedder/embedder.h"
-#include "mojo/edk/embedder/named_platform_channel_pair.h"
 #include "mojo/edk/embedder/platform_channel_pair.h"
-#include "mojo/edk/embedder/scoped_platform_handle.h"
-#include "ppapi/features/features.h"
-
-#if defined(OS_WIN)
-#include "base/files/file_path.h"
-#include "base/win/scoped_handle.h"
-#include "base/win/win_util.h"
-#include "content/common/sandbox_win.h"
-#include "content/public/common/sandbox_init.h"
-#include "sandbox/win/src/sandbox_types.h"
-#elif defined(OS_MACOSX)
-#include "content/browser/bootstrap_sandbox_manager_mac.h"
-#include "content/browser/mach_broker_mac.h"
-#include "sandbox/mac/bootstrap_sandbox.h"
-#include "sandbox/mac/pre_exec_delegate.h"
-#elif defined(OS_ANDROID)
-#include "base/android/jni_android.h"
-#include "content/browser/android/child_process_launcher_android.h"
-#elif defined(OS_POSIX)
-#include "base/memory/singleton.h"
-#include "content/browser/renderer_host/render_sandbox_host_linux.h"
-#include "content/browser/zygote_host/zygote_communication_linux.h"
-#include "content/browser/zygote_host/zygote_host_impl_linux.h"
-#include "content/common/child_process_sandbox_support_impl_linux.h"
-#include "content/public/browser/zygote_handle_linux.h"
-#endif
-
-#if defined(OS_POSIX)
-#include "base/posix/global_descriptors.h"
-#include "content/browser/file_descriptor_info_impl.h"
-#include "gin/v8_initializer.h"
-#endif
 
 namespace content {
 
 namespace {
 
-typedef base::Callback<void(ZygoteHandle,
-#if defined(OS_ANDROID)
-                            base::ScopedFD,
-#endif
-                            base::Process,
-                            int)>
-    NotifyCallback;
-
 void RecordHistogramsOnLauncherThread(base::TimeDelta launch_time) {
   DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
   // Log the launch time, separating out the first one (which will likely be
@@ -86,304 +34,11 @@ void RecordHistogramsOnLauncherThread(base::TimeDelta launch_time) {
   }
 }
 
-#if defined(OS_ANDROID)
-// TODO(sievers): Remove this by defining better what happens on what
-// thread in the corresponding Java code.
-void OnChildProcessStartedAndroid(const NotifyCallback& callback,
-                                  BrowserThread::ID client_thread_id,
-                                  const base::TimeTicks begin_launch_time,
-                                  base::ScopedFD mojo_fd,
-                                  base::ProcessHandle handle) {
-  int launch_result = (handle == base::kNullProcessHandle)
-                          ? LAUNCH_RESULT_FAILURE
-                          : LAUNCH_RESULT_SUCCESS;
-  // This can be called on the launcher thread or UI thread.
-  base::TimeDelta launch_time = base::TimeTicks::Now() - begin_launch_time;
-  BrowserThread::PostTask(
-      BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
-      base::Bind(&RecordHistogramsOnLauncherThread, launch_time));
-
-  base::Closure callback_on_client_thread(
-      base::Bind(callback, nullptr, base::Passed(&mojo_fd),
-                 base::Passed(base::Process(handle)), launch_result));
-  if (BrowserThread::CurrentlyOn(client_thread_id)) {
-    callback_on_client_thread.Run();
-  } else {
-    BrowserThread::PostTask(
-        client_thread_id, FROM_HERE, callback_on_client_thread);
-  }
-}
-#endif
-
-void LaunchOnLauncherThread(
-    const NotifyCallback& callback,
-    BrowserThread::ID client_thread_id,
-    int child_process_id,
-    std::unique_ptr<SandboxedProcessLauncherDelegate> delegate,
-    mojo::edk::ScopedPlatformHandle client_handle,
-    std::unique_ptr<base::CommandLine> cmd_line) {
-  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
-#if !defined(OS_ANDROID)
-  ZygoteHandle zygote = nullptr;
-  int launch_result = LAUNCH_RESULT_FAILURE;
-#endif
-#if defined(OS_WIN)
-  bool launch_elevated = delegate->ShouldLaunchElevated();
-#elif defined(OS_MACOSX)
-  base::EnvironmentMap env = delegate->GetEnvironment();
-#elif defined(OS_POSIX) && !defined(OS_ANDROID)
-  base::EnvironmentMap env = delegate->GetEnvironment();
-#endif
-  base::TimeTicks begin_launch_time = base::TimeTicks::Now();
-
-  base::Process process;
-#if defined(OS_WIN)
-  if (launch_elevated) {
-    // When establishing a Mojo connection, the pipe path has already been added
-    // to the command line.
-    base::LaunchOptions options;
-    options.start_hidden = true;
-    process = base::LaunchElevatedProcess(*cmd_line, options);
-  } else {
-    base::HandlesToInheritVector handles;
-    handles.push_back(client_handle.get().handle);
-    base::FieldTrialList::AppendFieldTrialHandleIfNeeded(&handles);
-    cmd_line->AppendSwitchASCII(
-        mojo::edk::PlatformChannelPair::kMojoPlatformChannelHandleSwitch,
-        base::UintToString(base::win::HandleToUint32(handles[0])));
-    launch_result = StartSandboxedProcess(
-        delegate.get(), cmd_line.get(), handles, &process);
-  }
-#elif defined(OS_POSIX)
-  std::string process_type =
-      cmd_line->GetSwitchValueASCII(switches::kProcessType);
-  std::unique_ptr<FileDescriptorInfo> files_to_register(
-      FileDescriptorInfoImpl::Create());
-
-  base::ScopedFD mojo_fd(client_handle.release().handle);
-  DCHECK(mojo_fd.is_valid());
-
-  int field_trial_handle = base::FieldTrialList::GetFieldTrialHandle();
-  if (field_trial_handle != base::kInvalidPlatformFile)
-    files_to_register->Share(kFieldTrialDescriptor, field_trial_handle);
-#if defined(OS_ANDROID)
-  files_to_register->Share(kMojoIPCChannel, mojo_fd.get());
-#else
-  files_to_register->Transfer(kMojoIPCChannel, std::move(mojo_fd));
-#endif
-#endif
-
-#if defined(OS_POSIX) && !defined(OS_MACOSX)
-  GetContentClient()->browser()->GetAdditionalMappedFilesForChildProcess(
-      *cmd_line, child_process_id, files_to_register.get());
-#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  bool snapshot_loaded = false;
-  base::MemoryMappedFile::Region region;
-#if defined(OS_ANDROID)
-  auto maybe_register = [&region, &files_to_register](int key, int fd) {
-    if (fd != -1)
-      files_to_register->ShareWithRegion(key, fd, region);
-  };
-  maybe_register(
-      kV8NativesDataDescriptor,
-      gin::V8Initializer::GetOpenNativesFileForChildProcesses(&region));
-  maybe_register(
-      kV8SnapshotDataDescriptor32,
-      gin::V8Initializer::GetOpenSnapshotFileForChildProcesses(&region, true));
-  maybe_register(
-      kV8SnapshotDataDescriptor64,
-      gin::V8Initializer::GetOpenSnapshotFileForChildProcesses(&region, false));
-
-  snapshot_loaded = true;
-#else
-  base::PlatformFile natives_pf =
-      gin::V8Initializer::GetOpenNativesFileForChildProcesses(&region);
-  DCHECK_GE(natives_pf, 0);
-  files_to_register->ShareWithRegion(
-      kV8NativesDataDescriptor, natives_pf, region);
-
-  base::PlatformFile snapshot_pf =
-      gin::V8Initializer::GetOpenSnapshotFileForChildProcesses(&region);
-  // Failure to load the V8 snapshot is not necessarily an error. V8 can start
-  // up (slower) without the snapshot.
-  if (snapshot_pf != -1) {
-    snapshot_loaded = true;
-    files_to_register->ShareWithRegion(
-        kV8SnapshotDataDescriptor, snapshot_pf, region);
-  }
-#endif
-
-  if (process_type != switches::kZygoteProcess) {
-    cmd_line->AppendSwitch(::switches::kV8NativesPassedByFD);
-    if (snapshot_loaded) {
-      cmd_line->AppendSwitch(::switches::kV8SnapshotPassedByFD);
-    }
-  }
-#endif  // defined(V8_USE_EXTERNAL_STARTUP_DATA)
-#endif  // defined(OS_POSIX) && !defined(OS_MACOSX)
-
-#if defined(OS_ANDROID)
-#if ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_FILE
-  base::MemoryMappedFile::Region icu_region;
-  base::PlatformFile icu_pf = base::i18n::GetIcuDataFileHandle(&icu_region);
-  files_to_register->ShareWithRegion(
-      kAndroidICUDataDescriptor, icu_pf, icu_region);
-#endif  // ICU_UTIL_DATA_IMPL == ICU_UTIL_DATA_FILE
-
-  // Android WebView runs in single process, ensure that we never get here
-  // when running in single process mode.
-  CHECK(!cmd_line->HasSwitch(switches::kSingleProcess));
-
-  StartChildProcess(
-      cmd_line->argv(), child_process_id, std::move(files_to_register),
-      base::Bind(&OnChildProcessStartedAndroid, callback, client_thread_id,
-                 begin_launch_time, base::Passed(&mojo_fd)));
-
-#elif defined(OS_POSIX)
-  // We need to close the client end of the IPC channel to reliably detect
-  // child termination.
-
-#if !defined(OS_MACOSX)
-  ZygoteHandle* zygote_handle =
-      !base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kNoZygote)
-          ? delegate->GetZygote()
-          : nullptr;
-  // If |zygote_handle| is null, a zygote should not be used.
-  if (zygote_handle) {
-    // This code runs on the PROCESS_LAUNCHER thread so race conditions are not
-    // an issue with the lazy initialization.
-    if (*zygote_handle == nullptr) {
-      *zygote_handle = CreateZygote();
-    }
-    zygote = *zygote_handle;
-    base::ProcessHandle handle = zygote->ForkRequest(
-        cmd_line->argv(), std::move(files_to_register), process_type);
-    process = base::Process(handle);
-  } else
-  // Fall through to the normal posix case below when we're not zygoting.
-#endif  // !defined(OS_MACOSX)
-  {
-    // Convert FD mapping to FileHandleMappingVector
-    base::FileHandleMappingVector fds_to_map =
-        files_to_register->GetMappingWithIDAdjustment(
-            base::GlobalDescriptors::kBaseDescriptor);
-
-#if !defined(OS_MACOSX)
-    if (process_type == switches::kRendererProcess) {
-      const int sandbox_fd =
-          RenderSandboxHostLinux::GetInstance()->GetRendererSocket();
-      fds_to_map.push_back(std::make_pair(
-          sandbox_fd,
-          GetSandboxFD()));
-    }
-#endif  // defined(OS_MACOSX)
-
-    // Actually launch the app.
-    base::LaunchOptions options;
-    options.environ = env;
-    options.fds_to_remap = &fds_to_map;
-
-#if defined(OS_MACOSX)
-    // Hold the MachBroker lock for the duration of LaunchProcess. The child
-    // will send its task port to the parent almost immediately after startup.
-    // The Mach message will be delivered to the parent, but updating the
-    // record of the launch will wait until after the placeholder PID is
-    // inserted below. This ensures that while the child process may send its
-    // port to the parent prior to the parent leaving LaunchProcess, the
-    // order in which the record in MachBroker is updated is correct.
-    MachBroker* broker = MachBroker::GetInstance();
-    broker->GetLock().Acquire();
-
-    // Make sure the MachBroker is running, and inform it to expect a
-    // check-in from the new process.
-    broker->EnsureRunning();
-
-    const SandboxType sandbox_type = delegate->GetSandboxType();
-    std::unique_ptr<sandbox::PreExecDelegate> pre_exec_delegate;
-    if (BootstrapSandboxManager::ShouldEnable()) {
-      BootstrapSandboxManager* sandbox_manager =
-          BootstrapSandboxManager::GetInstance();
-      if (sandbox_manager->EnabledForSandbox(sandbox_type)) {
-        pre_exec_delegate = sandbox_manager->sandbox()->NewClient(sandbox_type);
-      }
-    }
-    options.pre_exec_delegate = pre_exec_delegate.get();
-#endif  // defined(OS_MACOSX)
-
-    process = base::LaunchProcess(*cmd_line, options);
-
-#if defined(OS_MACOSX)
-    if (process.IsValid()) {
-      broker->AddPlaceholderForPid(process.Pid(), child_process_id);
-    } else {
-      if (pre_exec_delegate) {
-        BootstrapSandboxManager::GetInstance()->sandbox()->RevokeToken(
-            pre_exec_delegate->sandbox_token());
-      }
-    }
-
-    // After updating the broker, release the lock and let the child's
-    // message be processed on the broker's thread.
-    broker->GetLock().Release();
-#endif  // defined(OS_MACOSX)
-  }
-#endif  // else defined(OS_POSIX)
-#if !defined(OS_ANDROID)
-  if (process.IsValid()) {
-    launch_result = LAUNCH_RESULT_SUCCESS;
-    RecordHistogramsOnLauncherThread(base::TimeTicks::Now() -
-                                     begin_launch_time);
-  }
-  BrowserThread::PostTask(client_thread_id, FROM_HERE,
-                          base::Bind(callback, zygote, base::Passed(&process),
-                                     launch_result));
-#endif  // !defined(OS_ANDROID)
-}
-
-void TerminateOnLauncherThread(ZygoteHandle zygote, base::Process process) {
-  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
-#if defined(OS_ANDROID)
-  VLOG(1) << "ChromeProcess: Stopping process with handle "
-          << process.Handle();
-  StopChildProcess(process.Handle());
-#else
-  // Client has gone away, so just kill the process.  Using exit code 0
-  // means that UMA won't treat this as a crash.
-  process.Terminate(RESULT_CODE_NORMAL_EXIT, false);
-  // On POSIX, we must additionally reap the child.
-#if defined(OS_POSIX)
-#if !defined(OS_MACOSX)
-  if (zygote) {
-    // If the renderer was created via a zygote, we have to proxy the reaping
-    // through the zygote process.
-    zygote->EnsureProcessTerminated(process.Handle());
-  } else
-#endif  // !OS_MACOSX
-    base::EnsureProcessTerminated(std::move(process));
-#endif  // OS_POSIX
-#endif  // defined(OS_ANDROID)
-}
-
-void SetProcessBackgroundedOnLauncherThread(base::Process process,
-                                            bool background) {
-  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
-  if (process.CanBackgroundProcesses()) {
-#if defined(OS_MACOSX)
-    process.SetProcessBackgrounded(MachBroker::GetInstance(), background);
-#else
-    process.SetProcessBackgrounded(background);
-#endif  // defined(OS_MACOSX)
-  }
-#if defined(OS_ANDROID)
-  SetChildProcessInForeground(process.Handle(), !background);
-#endif
-}
-
 }  // namespace
 
 ChildProcessLauncher::ChildProcessLauncher(
     std::unique_ptr<SandboxedProcessLauncherDelegate> delegate,
-    std::unique_ptr<base::CommandLine> cmd_line,
+    std::unique_ptr<base::CommandLine> command_line,
     int child_process_id,
     Client* client,
     const std::string& mojo_child_token,
@@ -406,95 +61,118 @@ ChildProcessLauncher::ChildProcessLauncher(
       weak_factory_(this) {
   DCHECK(CalledOnValidThread());
   CHECK(BrowserThread::GetCurrentThreadIdentifier(&client_thread_id_));
-  Launch(std::move(delegate), std::move(cmd_line), child_process_id);
+
+  helper_ = new Helper(child_process_id, client_thread_id_,
+                       std::move(command_line), std::move(delegate),
+                       weak_factory_.GetWeakPtr(), terminate_on_shutdown);
+  helper_->LaunchOnClientThread();
 }
 
 ChildProcessLauncher::~ChildProcessLauncher() {
   DCHECK(CalledOnValidThread());
-  if (process_.IsValid() && terminate_child_on_shutdown_) {
-    // On Posix, EnsureProcessTerminated can lead to 2 seconds of sleep!  So
-    // don't this on the UI/IO threads.
-    BrowserThread::PostTask(BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
-                            base::Bind(&TerminateOnLauncherThread, zygote_,
-                                       base::Passed(&process_)));
-  }
+  if (process_.IsValid() && terminate_child_on_shutdown_)
+    Terminate(zygote_, std::move(process_));
 }
 
-void ChildProcessLauncher::Launch(
+ChildProcessLauncher::Helper::Helper(

[boliu, 2017/01/12 02:00:07]

nit: group ChildProcessLauncher methods together and Helper methods together,
right now Helper methods are in the middle of ChildProcessLauncher methods

[Jay Civelli, 2017/01/12 23:05:40]

Done (they were defined in the order they were declared in the .h file)

+    int child_process_id,
+    BrowserThread::ID client_thread_id,
+    std::unique_ptr<base::CommandLine> command_line,
     std::unique_ptr<SandboxedProcessLauncherDelegate> delegate,
-    std::unique_ptr<base::CommandLine> cmd_line,
-    int child_process_id) {
-  DCHECK(CalledOnValidThread());
+    const base::WeakPtr<ChildProcessLauncher>& child_process_launcher,
+    bool terminate_on_shutdown)
+    : child_process_id_(child_process_id),
+      client_thread_id_(client_thread_id),
+      command_line_(std::move(command_line)),
+      delegate_(std::move(delegate)),
+      child_process_launcher_(child_process_launcher),
+      terminate_on_shutdown_(terminate_on_shutdown) {
+}
 
-#if defined(OS_ANDROID)
-  // Android only supports renderer, sandboxed utility and gpu.
-  std::string process_type =
-      cmd_line->GetSwitchValueASCII(switches::kProcessType);
-  CHECK(process_type == switches::kGpuProcess ||
-        process_type == switches::kRendererProcess ||
-#if BUILDFLAG(ENABLE_PLUGINS)
-        process_type == switches::kPpapiPluginProcess ||
-#endif
-        process_type == switches::kUtilityProcess)
-      << "Unsupported process type: " << process_type;
+ChildProcessLauncher::Helper::~Helper() {}
 
-  // Non-sandboxed utility or renderer process are currently not supported.
-  DCHECK(process_type == switches::kGpuProcess ||
-         !cmd_line->HasSwitch(switches::kNoSandbox));
+void ChildProcessLauncher::Helper::LaunchOnClientThread() {
+  DCHECK_CURRENTLY_ON(client_thread_id_);
 
-#endif
-  mojo::edk::ScopedPlatformHandle server_handle;
-  mojo::edk::ScopedPlatformHandle client_handle;
-#if defined(OS_WIN)
-  if (delegate->ShouldLaunchElevated()) {
-    mojo::edk::NamedPlatformChannelPair named_pair;
-    server_handle = named_pair.PassServerHandle();
-    named_pair.PrepareToPassClientHandleToChildProcess(cmd_line.get());
-  } else
-#endif
-  {
+  BeforeLaunchOnClientThread();
+
+  mojo_server_handle_ = PrepareMojoPipeHandlesOnClientThread();
+  if (!mojo_server_handle_.is_valid()) {
     mojo::edk::PlatformChannelPair channel_pair;
-    server_handle = channel_pair.PassServerHandle();
-    client_handle = channel_pair.PassClientHandle();
+    mojo_server_handle_ = channel_pair.PassServerHandle();
+    mojo_client_handle_ = channel_pair.PassClientHandle();
   }
-  NotifyCallback reply_callback(base::Bind(&ChildProcessLauncher::DidLaunch,
-                                           weak_factory_.GetWeakPtr(),
-                                           terminate_child_on_shutdown_,
-                                           base::Passed(&server_handle)));
+
   BrowserThread::PostTask(
       BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
-      base::Bind(&LaunchOnLauncherThread, reply_callback, client_thread_id_,
-                 child_process_id, base::Passed(&delegate),
-                 base::Passed(&client_handle), base::Passed(&cmd_line)));
+      base::Bind(&Helper::LaunchOnLauncherThread, this));
 }
 
-void ChildProcessLauncher::UpdateTerminationStatus(bool known_dead) {
-  DCHECK(CalledOnValidThread());
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
-  if (zygote_) {
-    termination_status_ = zygote_->GetTerminationStatus(
-        process_.Handle(), known_dead, &exit_code_);
-  } else if (known_dead) {
-    termination_status_ =
-        base::GetKnownDeadTerminationStatus(process_.Handle(), &exit_code_);
-  } else {
-#elif defined(OS_MACOSX)
-  if (known_dead) {
-    termination_status_ =
-        base::GetKnownDeadTerminationStatus(process_.Handle(), &exit_code_);
-  } else {
-#elif defined(OS_ANDROID)
-  if (IsChildProcessOomProtected(process_.Handle())) {
-    termination_status_ = base::TERMINATION_STATUS_OOM_PROTECTED;
+void ChildProcessLauncher::Helper::LaunchOnLauncherThread() {
+  DCHECK_CURRENTLY_ON(BrowserThread::PROCESS_LAUNCHER);
+
+  begin_launch_time_ = base::TimeTicks::Now();
+
+  std::unique_ptr<FileMappedForLaunch> files_to_register = GetFilesToMap();
+
+  base::Process process;
+  ZygoteHandle zygote = nullptr;
+  bool is_synchronous_launch = true;
+  int launch_result = LAUNCH_RESULT_FAILURE;
+  if (ShouldForkAsZygote()) {
+    zygote = ForkAsZygote(std::move(files_to_register), &process);
+    launch_result = LAUNCH_RESULT_SUCCESS;
   } else {
-#else
-  {
-#endif
-    termination_status_ =
-      base::GetTerminationStatus(process_.Handle(), &exit_code_);
+    base::LaunchOptions options;
+    BeforeLaunchOnLauncherThread(*files_to_register, &options);
+
+    process = LaunchProcessOnLauncherThread(options,
+                                            files_to_register.get(),
+                                            &is_synchronous_launch,
+                                            &launch_result);
+
+    AfterLaunchOnLauncherThread(process, options);
+  }
+
+  if (is_synchronous_launch) {
+    PostLaunchOnLauncherThread(std::move(process), zygote, launch_result);
   }
 }
 
+void ChildProcessLauncher::Helper::PostLaunchOnLauncherThread(
+    base::Process process,
+    ZygoteHandle zygote,
+    int launch_result) {
+  // Release the client handle now that the process has been started (the pipe
+  // may not signal when the process dies otherwise and we would not detect the
+  // child process died).
+  mojo_client_handle_.reset();
+
+  if (process.IsValid()) {

[boliu, 2017/01/12 02:00:07]

on android, old code didn't check this to record histogram

[Jay Civelli, 2017/01/12 23:05:40]

Yes, and that seemed wrong (the other platforms behavior seemed right). I don't
think we want to include the time it takes for a process to fail to start in the
metrics measuring how long it takes for a process to start.

+    RecordHistogramsOnLauncherThread(
+        base::TimeTicks::Now() - begin_launch_time_);
+  }
+
+  BrowserThread::PostTask(
+      client_thread_id_, FROM_HERE,
+      base::Bind(&Helper::PostLaunchOnClientThread,
+          this, base::Passed(&process), zygote, launch_result));
+}
+
+void ChildProcessLauncher::Helper::PostLaunchOnClientThread(
+    base::Process process, ZygoteHandle zygote, int error_code) {
+  if (child_process_launcher_) {
+    child_process_launcher_->Notify(zygote, std::move(mojo_server_handle_),
+        std::move(process), error_code);
+  } else if (process.IsValid() && terminate_on_shutdown_) {
+    ChildProcessLauncher::Terminate(zygote, std::move(process));
+  }
+}
+
+std::string ChildProcessLauncher::Helper::GetProcessType() {
+  return command_line()->GetSwitchValueASCII(switches::kProcessType);
+}
+
 void ChildProcessLauncher::SetProcessBackgrounded(bool background) {
   DCHECK(CalledOnValidThread());
   base::Process to_pass = process_.Duplicate();
@@ -503,33 +181,6 @@ void ChildProcessLauncher::SetProcessBackgrounded(bool background) {
                                      base::Passed(&to_pass), background));
 }
 
-void ChildProcessLauncher::DidLaunch(
-    base::WeakPtr<ChildProcessLauncher> instance,
-    bool terminate_on_shutdown,
-    mojo::edk::ScopedPlatformHandle server_handle,
-    ZygoteHandle zygote,
-#if defined(OS_ANDROID)
-    base::ScopedFD mojo_fd,
-#endif
-    base::Process process,
-    int error_code) {
-  if (!process.IsValid())
-    LOG(ERROR) << "Failed to launch child process";
-
-  if (instance.get()) {
-    instance->Notify(zygote, std::move(server_handle),
-                     std::move(process), error_code);
-  } else {
-    if (process.IsValid() && terminate_on_shutdown) {
-      // On Posix, EnsureProcessTerminated can lead to 2 seconds of sleep!  So
-      // don't this on the UI/IO threads.
-      BrowserThread::PostTask(BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
-                              base::Bind(&TerminateOnLauncherThread, zygote,
-                                         base::Passed(&process)));
-    }
-  }
-}
-
 void ChildProcessLauncher::Notify(ZygoteHandle zygote,
                                   mojo::edk::ScopedPlatformHandle server_handle,
                                   base::Process process,
@@ -544,9 +195,7 @@ void ChildProcessLauncher::Notify(ZygoteHandle zygote,
                                     mojo_child_token_, process_error_callback_);
   }
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
   zygote_ = zygote;
-#endif
   if (process_.IsValid()) {
     client_->OnProcessLaunched();
   } else {
@@ -564,7 +213,7 @@ bool ChildProcessLauncher::IsStarting() {
 
 const base::Process& ChildProcessLauncher::GetProcess() const {
   // TODO(crbug.com/469248): This fails in some tests.
-  // DCHECK(CalledOnValidThread());
+  //  DCHECK(CalledOnValidThread());
   return process_;
 }
 
@@ -583,18 +232,22 @@ base::TerminationStatus ChildProcessLauncher::GetChildTerminationStatus(
   if (exit_code)
     *exit_code = exit_code_;
 
-  // POSIX: If the process crashed, then the kernel closed the socket
-  // for it and so the child has already died by the time we get
-  // here. Since GetTerminationStatus called waitpid with WNOHANG,
-  // it'll reap the process.  However, if GetTerminationStatus didn't
-  // reap the child (because it was still running), we'll need to
-  // Terminate via ProcessWatcher. So we can't close the handle here.
+  // POSIX: If the process crashed, then the kernel closed the socket for it and
+  // so the child has already died by the time we get here. Since
+  // GetTerminationStatus called waitpid with WNOHANG, it'll reap the process.
+  // However, if GetTerminationStatus didn't reap the child (because it was
+  // still running), we'll need to Terminate via ProcessWatcher. So we can't
+  // close the handle here.
   if (termination_status_ != base::TERMINATION_STATUS_STILL_RUNNING)
     process_.Close();
 
   return termination_status_;
 }
 
+bool ChildProcessLauncher::Terminate(int exit_code, bool wait) {
+  return IsStarting() ? false : TerminateProcess(GetProcess(), exit_code, wait);
+}
+
 ChildProcessLauncher::Client* ChildProcessLauncher::ReplaceClientForTest(
     Client* client) {
   Client* ret = client_;
@@ -602,4 +255,20 @@ ChildProcessLauncher::Client* ChildProcessLauncher::ReplaceClientForTest(
   return ret;
 }
 
+// static
+void ChildProcessLauncher::Terminate(
+    ZygoteHandle zygote, base::Process process) {
+  if (BrowserThread::CurrentlyOn(BrowserThread::PROCESS_LAUNCHER)) {
+    ChildProcessLauncher::TerminateOnLauncherThread(zygote, std::move(process));
+    return;
+  }
+  // On Posix, EnsureProcessTerminated can lead to 2 seconds of sleep!  So don't
+  // this on the UI/IO threads.
+  BrowserThread::PostTask(
+      BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
+      base::Bind(&ChildProcessLauncher::TerminateOnLauncherThread,
+                 zygote, base::Passed(&process)));
+}
+
+
 }  // namespace content