Revive experiment to isolate shell operations.

chrome/browser/win/chrome_select_file_dialog_factory.cc

Index: chrome/browser/win/chrome_select_file_dialog_factory.cc
diff --git a/chrome/browser/win/chrome_select_file_dialog_factory.cc b/chrome/browser/win/chrome_select_file_dialog_factory.cc
index 668f30ca4d2aac1621614355f87f6a05fe885d60..44c8494d5be0c2befc0bec2b8139750c14683355 100644
--- a/chrome/browser/win/chrome_select_file_dialog_factory.cc
+++ b/chrome/browser/win/chrome_select_file_dialog_factory.cc
@@ -7,316 +7,198 @@
 #include <Windows.h>
 #include <commdlg.h>
 
+#include <vector>
+
 #include "base/bind.h"
 #include "base/bind_helpers.h"
-#include "base/callback.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/metrics/field_trial.h"
-#include "base/strings/string16.h"
+#include "base/feature_list.h"
+#include "base/strings/string_util.h"
 #include "base/synchronization/waitable_event.h"
-#include "chrome/common/chrome_utility_messages.h"
+#include "base/win/win_util.h"
+#include "chrome/common/shell_handler_win.mojom.h"
 #include "chrome/grit/generated_resources.h"
-#include "content/public/browser/utility_process_host.h"
-#include "content/public/browser/utility_process_host_client.h"
-#include "ipc/ipc_message_macros.h"
+#include "content/public/browser/utility_process_mojo_client.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/win/open_file_name_win.h"
 #include "ui/shell_dialogs/select_file_dialog_win.h"
 
 namespace {
 
-bool ShouldIsolateShellOperations() {
-  return base::FieldTrialList::FindFullName("IsolateShellOperations") ==
-         "Enabled";
-}
+constexpr base::Feature kIsolateShellOperations{
+    "IsolateShellOperations", base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Receives the GetOpenFileName result from the utility process.
-class GetOpenFileNameClient : public content::UtilityProcessHostClient {
+// Implements GetOpenFileName() and GetSaveFileName() for
+// CreateWinSelectFileDialog by delegating to a utility process.
+class OpenFileNameClient {
  public:
-  GetOpenFileNameClient();
-
-  // Blocks until the GetOpenFileName result is received (including failure to
-  // launch or a crash of the utility process).
-  void WaitForCompletion();
+  OpenFileNameClient();
 
-  // Returns the selected directory.
-  const base::FilePath& directory() const { return directory_; }
+  // Invokes ::GetOpenFileName() and stores the result into |directory| and
+  // |filenames|. Returns false on failure.
+  bool BlockingGetOpenFileName(OPENFILENAME* ofn);
 
-  // Returns the list of selected filenames. Each should be interpreted as a
-  // child of directory().
-  const std::vector<base::FilePath>& filenames() const { return filenames_; }
-
-  // UtilityProcessHostClient implementation
-  void OnProcessCrashed(int exit_code) override;
-  void OnProcessLaunchFailed(int error_code) override;
-  bool OnMessageReceived(const IPC::Message& message) override;
-
- protected:
-  ~GetOpenFileNameClient() override;
+  // Invokes ::GetSaveFileName() and stores the result into |path| and
+  // |one_based_filter_index|. Returns false on failure.
+  bool BlockingGetSaveFileName(OPENFILENAME* ofn);
 
  private:
-  void OnResult(const base::FilePath& directory,
-                const std::vector<base::FilePath>& filenames);
-  void OnFailure();
+  void StartClient();
 
-  base::FilePath directory_;
-  std::vector<base::FilePath> filenames_;
-  base::WaitableEvent event_;
+  void InvokeGetOpenFileNameOnIOThread(OPENFILENAME* ofn);
+  void InvokeGetSaveFileNameOnIOThread(OPENFILENAME* ofn);
 
-  DISALLOW_COPY_AND_ASSIGN(GetOpenFileNameClient);
-};
+  // Callbacks for Mojo invokation.
+  void OnDidGetOpenFileNames(const base::FilePath& directory,
+                             mojo::Array<base::FilePath> filenames);
+  void OnDidGetSaveFileName(const base::FilePath& path,
+                            uint32_t one_based_filter_index);
 
-GetOpenFileNameClient::GetOpenFileNameClient()
-    : event_(base::WaitableEvent::ResetPolicy::MANUAL,
-             base::WaitableEvent::InitialState::NOT_SIGNALED) {}
+  void OnConnectionError();
 
-void GetOpenFileNameClient::WaitForCompletion() {
-  event_.Wait();
-}
+  // Must only be accessed on the IO thread.
+  std::unique_ptr<content::UtilityProcessMojoClient<mojom::ShellHandler>>
+      client_;
 
-void GetOpenFileNameClient::OnProcessCrashed(int exit_code) {
-  event_.Signal();
-}
+  // This is used to block until the result is received.
+  base::WaitableEvent result_received_event_;
 
-void GetOpenFileNameClient::OnProcessLaunchFailed(int error_code) {
-  event_.Signal();
-}
+  // Result variables for GetOpenFileName.
+  base::FilePath directory_;
+  std::vector<base::FilePath> filenames_;
 
-bool GetOpenFileNameClient::OnMessageReceived(const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(GetOpenFileNameClient, message)
-    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_GetOpenFileName_Failed,
-                        OnFailure)
-    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_GetOpenFileName_Result,
-                        OnResult)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
+  // Result variables for GetSaveFileName.
+  base::FilePath path_;
+  DWORD one_based_filter_index_ = 0;
 
-GetOpenFileNameClient::~GetOpenFileNameClient() {}
+  DISALLOW_COPY_AND_ASSIGN(OpenFileNameClient);
+};
 
-void GetOpenFileNameClient::OnResult(
-    const base::FilePath& directory,
-    const std::vector<base::FilePath>& filenames) {
-  directory_ = directory;
-  filenames_ = filenames;
-  event_.Signal();
-}
+OpenFileNameClient::OpenFileNameClient()
+    : result_received_event_(base::WaitableEvent::ResetPolicy::MANUAL,
+                             base::WaitableEvent::InitialState::NOT_SIGNALED) {}
 
-void GetOpenFileNameClient::OnFailure() {
-  event_.Signal();
-}
+bool OpenFileNameClient::BlockingGetOpenFileName(OPENFILENAME* ofn) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&OpenFileNameClient::InvokeGetOpenFileNameOnIOThread,
+                 base::Unretained(this), ofn));
 
-// Initiates IPC with a new utility process using |client|. Instructs the
-// utility process to call GetOpenFileName with |ofn|. |current_task_runner|
-// must be the currently executing task runner.
-void DoInvokeGetOpenFileName(
-    OPENFILENAME* ofn,
-    scoped_refptr<GetOpenFileNameClient> client,
-    const scoped_refptr<base::SequencedTaskRunner>& current_task_runner) {
-  DCHECK(current_task_runner->RunsTasksOnCurrentThread());
-
-  base::WeakPtr<content::UtilityProcessHost> utility_process_host(
-      content::UtilityProcessHost::Create(client, current_task_runner)
-      ->AsWeakPtr());
-  utility_process_host->SetName(l10n_util::GetStringUTF16(
-      IDS_UTILITY_PROCESS_FILE_DIALOG_NAME));
-  utility_process_host->DisableSandbox();
-  utility_process_host->Send(new ChromeUtilityMsg_GetOpenFileName(
-      ofn->hwndOwner,
-      ofn->Flags & ~OFN_ENABLEHOOK,  // We can't send a hook function over IPC.
-      ui::win::OpenFileName::GetFilters(ofn),
-      base::FilePath(ofn->lpstrInitialDir ? ofn->lpstrInitialDir
-                                          : base::string16()),
-      base::FilePath(ofn->lpstrFile)));
-}
+  result_received_event_.Wait();
 
-// Invokes GetOpenFileName in a utility process. Blocks until the result is
-// received. Uses |blocking_task_runner| for IPC.
-bool GetOpenFileNameInUtilityProcess(
-    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
-    OPENFILENAME* ofn) {
-  scoped_refptr<GetOpenFileNameClient> client(new GetOpenFileNameClient);
-  blocking_task_runner->PostTask(
-      FROM_HERE,
-      base::Bind(&DoInvokeGetOpenFileName,
-                 base::Unretained(ofn), client, blocking_task_runner));
-  client->WaitForCompletion();
-
-  if (client->filenames().empty())
+  if (filenames_.empty())
     return false;
 
-  ui::win::OpenFileName::SetResult(
-      client->directory(), client->filenames(), ofn);
+  ui::win::OpenFileName::SetResult(directory_, filenames_, ofn);
   return true;
 }
 
-// Implements GetOpenFileName for CreateWinSelectFileDialog by delegating to a
-// utility process.
-bool GetOpenFileNameImpl(
-    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
-    OPENFILENAME* ofn) {
-  if (ShouldIsolateShellOperations())
-    return GetOpenFileNameInUtilityProcess(blocking_task_runner, ofn);
-
-  return ::GetOpenFileName(ofn) == TRUE;
-}
-
-class GetSaveFileNameClient : public content::UtilityProcessHostClient {
- public:
-  GetSaveFileNameClient();
-
-  // Blocks until the GetSaveFileName result is received (including failure to
-  // launch or a crash of the utility process).
-  void WaitForCompletion();
-
-  // Returns the selected path.
-  const base::FilePath& path() const { return path_; }
-
-  // Returns the index of the user-selected filter.
-  int one_based_filter_index() const { return one_based_filter_index_; }
+bool OpenFileNameClient::BlockingGetSaveFileName(OPENFILENAME* ofn) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&OpenFileNameClient::InvokeGetSaveFileNameOnIOThread,
+                 base::Unretained(this), ofn));
 
-  // UtilityProcessHostClient implementation
-  void OnProcessCrashed(int exit_code) override;
-  void OnProcessLaunchFailed(int error_code) override;
-  bool OnMessageReceived(const IPC::Message& message) override;
+  result_received_event_.Wait();
 
- protected:
-  ~GetSaveFileNameClient() override;
+  if (path_.empty())
+    return false;
 
- private:
-  void OnResult(const base::FilePath& path, int one_based_filter_index);
-  void OnFailure();
+  base::wcslcpy(ofn->lpstrFile, path_.value().c_str(), ofn->nMaxFile);
+  ofn->nFilterIndex = one_based_filter_index_;
+  return true;
+}
 
-  base::FilePath path_;
-  int one_based_filter_index_;
-  base::WaitableEvent event_;
+void OpenFileNameClient::StartClient() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  client_.reset(new content::UtilityProcessMojoClient<mojom::ShellHandler>(
+      l10n_util::GetStringUTF16(IDS_UTILITY_PROCESS_FILE_DIALOG_NAME)));
 
-  DISALLOW_COPY_AND_ASSIGN(GetSaveFileNameClient);
-};
+  client_->set_disable_sandbox();
+  client_->set_error_callback(base::Bind(&OpenFileNameClient::OnConnectionError,
+                                         base::Unretained(this)));
 
-GetSaveFileNameClient::GetSaveFileNameClient()
-    : one_based_filter_index_(0),
-      event_(base::WaitableEvent::ResetPolicy::MANUAL,
-             base::WaitableEvent::InitialState::NOT_SIGNALED) {}
-
-void GetSaveFileNameClient::WaitForCompletion() {
-  event_.Wait();
+  client_->Start();
 }
 
-void GetSaveFileNameClient::OnProcessCrashed(int exit_code) {
-  event_.Signal();
+void OpenFileNameClient::InvokeGetOpenFileNameOnIOThread(OPENFILENAME* ofn) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  StartClient();
+  client_->service()->DoGetOpenFileName(
+      base::win::HandleToUint32(ofn->hwndOwner),
+      static_cast<uint32_t>(ofn->Flags), ui::win::OpenFileName::GetFilters(ofn),
+      ofn->lpstrInitialDir ? base::FilePath(ofn->lpstrInitialDir)
+                           : base::FilePath(),
+      base::FilePath(ofn->lpstrFile),
+      base::Bind(&OpenFileNameClient::OnDidGetOpenFileNames,
+                 base::Unretained(this)));
 }
 
-void GetSaveFileNameClient::OnProcessLaunchFailed(int error_code) {
-  event_.Signal();
+void OpenFileNameClient::InvokeGetSaveFileNameOnIOThread(OPENFILENAME* ofn) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  StartClient();
+  client_->service()->DoGetSaveFileName(
+      base::win::HandleToUint32(ofn->hwndOwner),
+      static_cast<uint32_t>(ofn->Flags), ui::win::OpenFileName::GetFilters(ofn),
+      ofn->nFilterIndex,
+      ofn->lpstrInitialDir ? base::FilePath(ofn->lpstrInitialDir)
+                           : base::FilePath(),
+      base::FilePath(ofn->lpstrFile),
+      ofn->lpstrDefExt ? base::FilePath(ofn->lpstrDefExt) : base::FilePath(),
+      base::Bind(&OpenFileNameClient::OnDidGetSaveFileName,
+                 base::Unretained(this)));
 }
 
-bool GetSaveFileNameClient::OnMessageReceived(const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(GetSaveFileNameClient, message)
-    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_GetSaveFileName_Failed,
-                        OnFailure)
-    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_GetSaveFileName_Result,
-                        OnResult)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
+void OpenFileNameClient::OnDidGetOpenFileNames(
+    const base::FilePath& directory,
+    mojo::Array<base::FilePath> filenames) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  client_.reset();
+  directory_ = directory;
+  filenames_ = filenames.storage();
 
-GetSaveFileNameClient::~GetSaveFileNameClient() {}
+  result_received_event_.Signal();
+}
 
-void GetSaveFileNameClient::OnResult(const base::FilePath& path,
-                                     int one_based_filter_index) {
+void OpenFileNameClient::OnDidGetSaveFileName(const base::FilePath& path,
+                                              uint32_t one_based_filter_index) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  client_.reset();
   path_ = path;
   one_based_filter_index_ = one_based_filter_index;
-  event_.Signal();
-}
 
-void GetSaveFileNameClient::OnFailure() {
-  event_.Signal();
+  result_received_event_.Signal();
 }
 
-// Initiates IPC with a new utility process using |client|. Instructs the
-// utility process to call GetSaveFileName with |ofn|. |current_task_runner|
-// must be the currently executing task runner.
-void DoInvokeGetSaveFileName(
-    OPENFILENAME* ofn,
-    scoped_refptr<GetSaveFileNameClient> client,
-    const scoped_refptr<base::SequencedTaskRunner>& current_task_runner) {
-  DCHECK(current_task_runner->RunsTasksOnCurrentThread());
-
-  base::WeakPtr<content::UtilityProcessHost> utility_process_host(
-      content::UtilityProcessHost::Create(client, current_task_runner)
-      ->AsWeakPtr());
-  utility_process_host->SetName(l10n_util::GetStringUTF16(
-      IDS_UTILITY_PROCESS_FILE_DIALOG_NAME));
-  utility_process_host->DisableSandbox();
-  ChromeUtilityMsg_GetSaveFileName_Params params;
-  params.owner = ofn->hwndOwner;
-  // We can't pass the hook function over IPC.
-  params.flags = ofn->Flags & ~OFN_ENABLEHOOK;
-  params.filters = ui::win::OpenFileName::GetFilters(ofn);
-  params.one_based_filter_index = ofn->nFilterIndex;
-  params.suggested_filename = base::FilePath(ofn->lpstrFile);
-  params.initial_directory = base::FilePath(
-      ofn->lpstrInitialDir ? ofn->lpstrInitialDir : base::string16());
-  params.default_extension =
-      ofn->lpstrDefExt ? base::string16(ofn->lpstrDefExt) : base::string16();
-
-  utility_process_host->Send(new ChromeUtilityMsg_GetSaveFileName(params));
+void OpenFileNameClient::OnConnectionError() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  client_.reset();
+  result_received_event_.Signal();
 }
 
-// Invokes GetSaveFileName in a utility process. Blocks until the result is
-// received. Uses |blocking_task_runner| for IPC.
-bool GetSaveFileNameInUtilityProcess(
-    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
-    OPENFILENAME* ofn) {
-  scoped_refptr<GetSaveFileNameClient> client(new GetSaveFileNameClient);
-  blocking_task_runner->PostTask(
-      FROM_HERE,
-      base::Bind(&DoInvokeGetSaveFileName,
-                 base::Unretained(ofn), client, blocking_task_runner));
-  client->WaitForCompletion();
-
-  if (client->path().empty())
-    return false;
-
-  base::wcslcpy(ofn->lpstrFile, client->path().value().c_str(), ofn->nMaxFile);
-  ofn->nFilterIndex = client->one_based_filter_index();
+bool GetOpenFileNameImpl(OPENFILENAME* ofn) {
+  if (base::FeatureList::IsEnabled(kIsolateShellOperations))
+    return OpenFileNameClient().BlockingGetOpenFileName(ofn);
 
-  return true;
+  return ::GetOpenFileName(ofn) == TRUE;
 }
 
-// Implements GetSaveFileName for CreateWinSelectFileDialog by delegating to a
-// utility process.
-bool GetSaveFileNameImpl(
-    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
-    OPENFILENAME* ofn) {
-  if (ShouldIsolateShellOperations())
-    return GetSaveFileNameInUtilityProcess(blocking_task_runner, ofn);
+bool GetSaveFileNameImpl(OPENFILENAME* ofn) {
+  if (base::FeatureList::IsEnabled(kIsolateShellOperations))
+    return OpenFileNameClient().BlockingGetSaveFileName(ofn);
 
   return ::GetSaveFileName(ofn) == TRUE;
 }
 
 }  // namespace
 
-ChromeSelectFileDialogFactory::ChromeSelectFileDialogFactory(
-    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner)
-    : blocking_task_runner_(blocking_task_runner) {
-}
+ChromeSelectFileDialogFactory::ChromeSelectFileDialogFactory() = default;
 
-ChromeSelectFileDialogFactory::~ChromeSelectFileDialogFactory() {}
+ChromeSelectFileDialogFactory::~ChromeSelectFileDialogFactory() = default;
 
 ui::SelectFileDialog* ChromeSelectFileDialogFactory::Create(
     ui::SelectFileDialog::Listener* listener,
     ui::SelectFilePolicy* policy) {
-  return ui::CreateWinSelectFileDialog(
-      listener,
-      policy,
-      base::Bind(GetOpenFileNameImpl, blocking_task_runner_),
-      base::Bind(GetSaveFileNameImpl, blocking_task_runner_));
+  return ui::CreateWinSelectFileDialog(listener, policy,
+                                       base::Bind(GetOpenFileNameImpl),
+                                       base::Bind(GetSaveFileNameImpl));
 }