Revert "exo: Move XkbTracker from WaylandKeyboardDelegate to Seat."

This reverts commit c1744bc0.

Reason for revert: Broke build: https://crbug.com/1132766

Original change's description:
> exo: Move XkbTracker from WaylandKeyboardDelegate to Seat.
>
> This is preparation to share XkbTracker with wayland IME server.
>
> BUG=1123705
> TEST=Built locally. Run exo_unittests.
>
> Change-Id: I7859c2193578cc5a18fa39a96c3fe86d2f39f4dc
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2428505
> Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
> Reviewed-by: Jun Mukai <mukai@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#810863}

TBR=mukai@chromium.org,hidehiko@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1123705,1132766
Change-Id: I92c8df6383ea569ca2b88780c6017c619e26d1af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2434097
Commit-Queue: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811383}

ash/public/cpp/external_arc/message_center/arc_notification_content_view_unittest.cc

@@ -29,7 +29,6 @@
 #include "components/exo/buffer.h"
 #include "components/exo/keyboard.h"
 #include "components/exo/keyboard_delegate.h"
-#include "components/exo/keyboard_modifiers.h"
 #include "components/exo/notification_surface.h"
 #include "components/exo/seat.h"
 #include "components/exo/surface.h"
@@ -76,15 +75,15 @@ class MockKeyboardDelegate : public exo::KeyboardDelegate {
               OnKeyboardKey,
               (base::TimeTicks, ui::DomCode, bool),
               (override));
-  MOCK_METHOD(void,
-              OnKeyboardModifiers,
-              (const exo::KeyboardModifiers&),
-              (override));
+  MOCK_METHOD(void, OnKeyboardModifiers, (int), (override));
   MOCK_METHOD(void,
               OnKeyRepeatSettingsChanged,
               (bool, base::TimeDelta, base::TimeDelta),
               (override));
-  MOCK_METHOD(void, OnKeyboardLayoutUpdated, (base::StringPiece), (override));
+  MOCK_METHOD(void,
+              OnKeyboardLayoutUpdated,
+              (const std::string& layout_name),
+              (override));
 };
 
 class FakeNotificationSurface : public exo::NotificationSurface {

components/exo/BUILD.gn

@@ -2,17 +2,9 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
 import("//testing/test.gni")
-import("//ui/base/ui_features.gni")
-
-if (use_xkbcommon) {
-  pkg_config("xkbcommon") {
-    packages = [ "xkbcommon" ]
-  }
-}
 
 static_library("exo") {
   sources = [
@@ -168,7 +160,6 @@ static_library("exo") {
       "xkb_tracker.cc",
       "xkb_tracker.h",
     ]
-    configs += [ ":xkbcommon" ]
   }
 
   if (is_chromecast) {

components/exo/keyboard.cc

@@ -14,13 +14,11 @@
 #include "components/exo/input_trace.h"
 #include "components/exo/keyboard_delegate.h"
 #include "components/exo/keyboard_device_configuration_delegate.h"
-#include "components/exo/keyboard_modifiers.h"
 #include "components/exo/seat.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/shell_surface_util.h"
 #include "components/exo/surface.h"
 #include "components/exo/wm_helper.h"
-#include "components/exo/xkb_tracker.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
@@ -171,7 +169,7 @@ Keyboard::Keyboard(std::unique_ptr<KeyboardDelegate> delegate, Seat* seat)
   ash::ImeControllerImpl* ime_controller = ash::Shell::Get()->ime_controller();
   ime_controller->AddObserver(this);
 
-  delegate_->OnKeyboardLayoutUpdated(seat_->xkb_tracker()->GetKeymap().get());
+  delegate_->OnKeyboardLayoutUpdated(ime_controller->keyboard_layout_name());
   OnSurfaceFocused(seat_->GetFocusedSurface());
   OnKeyRepeatSettingsChanged(
       ash::KeyboardController::Get()->GetKeyRepeatSettings());
@@ -280,9 +278,7 @@ void Keyboard::OnKeyEvent(ui::KeyEvent* event) {
       ConsumedByIme(focus_, event);
 
   // Always update modifiers.
-  // XkbTracker must be updated in the Seat, before calling this method.
-  // Ensured by the observer registration order.
-  delegate_->OnKeyboardModifiers(seat_->xkb_tracker()->GetModifiers());
+  delegate_->OnKeyboardModifiers(event->flags());
 
   // TODO(yhanada): This is a quick fix for https://crbug.com/859071. Remove
   // ARC-specific code path once we can find a way to manage press/release
@@ -405,9 +401,7 @@ void Keyboard::OnKeyRepeatSettingsChanged(
 void Keyboard::OnCapsLockChanged(bool enabled) {}
 
 void Keyboard::OnKeyboardLayoutNameChanged(const std::string& layout_name) {
-  // XkbTracker must be updated in the Seat, before calling this method.
-  // Ensured by the observer registration order.
-  delegate_->OnKeyboardLayoutUpdated(seat_->xkb_tracker()->GetKeymap().get());
+  delegate_->OnKeyboardLayoutUpdated(layout_name);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -422,7 +416,7 @@ void Keyboard::SetFocus(Surface* surface) {
   }
   if (surface) {
     pressed_keys_ = seat_->pressed_keys();
-    delegate_->OnKeyboardModifiers(seat_->xkb_tracker()->GetModifiers());
+    delegate_->OnKeyboardModifiers(seat_->modifier_flags());
     delegate_->OnKeyboardEnter(surface, pressed_keys_);
     focus_ = surface;
     focus_->AddSurfaceObserver(this);

components/exo/keyboard_delegate.h

@@ -7,7 +7,6 @@
 
 #include "base/containers/flat_map.h"
 #include "base/containers/flat_set.h"
-#include "base/strings/string_piece.h"
 #include "base/time/time.h"
 
 namespace ui {
@@ -15,7 +14,6 @@ enum class DomCode;
 }
 
 namespace exo {
-struct KeyboardModifiers;
 class Surface;
 
 // Handles events on keyboards in context-specific ways.
@@ -44,7 +42,7 @@ class KeyboardDelegate {
                                  bool pressed) = 0;
 
   // Called when keyboard modifier state changed.
-  virtual void OnKeyboardModifiers(const KeyboardModifiers& modifiers) = 0;
+  virtual void OnKeyboardModifiers(int modifier_flags) = 0;
 
   // Called when key repeat settings are changed.
   virtual void OnKeyRepeatSettingsChanged(bool enabled,
@@ -52,7 +50,9 @@ class KeyboardDelegate {
                                           base::TimeDelta interval) = 0;
 
   // Called when keyboard layout is updated.
-  virtual void OnKeyboardLayoutUpdated(base::StringPiece keymap) = 0;
+  // TODO(hidehiko): Update the argument to pass the keymap
+  // when XkbTracker is moved out from WaylandKeyboardDelegate.
+  virtual void OnKeyboardLayoutUpdated(const std::string& layout_name) = 0;
 };
 
 }  // namespace exo

components/exo/seat.cc

@@ -25,7 +25,6 @@
 #include "components/exo/shell_surface_util.h"
 #include "components/exo/surface.h"
 #include "components/exo/wm_helper.h"
-#include "components/exo/xkb_tracker.h"
 #include "services/data_decoder/public/cpp/decode_image.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/base/clipboard/clipboard_data_endpoint.h"
@@ -63,14 +62,6 @@ Seat::Seat() : changing_clipboard_data_to_selection_source_(false) {
     ui::PlatformEventSource::GetInstance()->AddPlatformEventObserver(this);
 #if defined(OS_CHROMEOS)
   ui_lock_controller_ = std::make_unique<UILockController>(this);
-
-  // Seat needs to be registered as observers before any Keyboard,
-  // because Keyboard expects that the XkbTracker is up-to-date when its
-  // observer method is called.
-  xkb_tracker_ = std::make_unique<XkbTracker>();
-  ash::ImeControllerImpl* ime_controller = ash::Shell::Get()->ime_controller();
-  xkb_tracker_->UpdateKeyboardLayout(ime_controller->keyboard_layout_name());
-  ime_controller->AddObserver(this);
 #endif
 }
 
@@ -83,9 +74,6 @@ void Seat::Shutdown() {
     return;
   shutdown_ = true;
   DCHECK(!selection_source_) << "DataSource must be released before Seat";
-#if defined(OS_CHROMEOS)
-  ash::Shell::Get()->ime_controller()->RemoveObserver(this);
-#endif
   WMHelper::GetInstance()->RemoveFocusObserver(this);
   WMHelper::GetInstance()->RemovePreTargetHandler(this);
   ui::ClipboardMonitor::GetInstance()->RemoveObserver(this);
@@ -303,9 +291,7 @@ void Seat::OnKeyEvent(ui::KeyEvent* event) {
         break;
     }
   }
-#if defined(OS_CHROMEOS)
-  xkb_tracker_->UpdateKeyboardModifiers(event->flags());
-#endif
+  modifier_flags_ = event->flags();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -318,17 +304,6 @@ void Seat::OnClipboardDataChanged() {
   selection_source_.reset();
 }
 
-#if defined(OS_CHROMEOS)
-////////////////////////////////////////////////////////////////////////////////
-// ash::ImeControllerImpl::Observer overrides:
-
-void Seat::OnCapsLockChanged(bool enabled) {}
-
-void Seat::OnKeyboardLayoutNameChanged(const std::string& layout_name) {
-  xkb_tracker_->UpdateKeyboardLayout(layout_name);
-}
-#endif
-
 ////////////////////////////////////////////////////////////////////////////////
 // DataSourceObserver overrides:
 

components/exo/seat.h

@@ -19,7 +19,6 @@
 #include "ui/events/platform/platform_event_observer.h"
 
 #if defined(OS_CHROMEOS)
-#include "ash/ime/ime_controller_impl.h"
 #include "components/exo/ui_lock_controller.h"
 #endif
 
@@ -33,7 +32,6 @@ class DragDropOperation;
 class ScopedDataSource;
 class SeatObserver;
 class Surface;
-class XkbTracker;
 
 // The maximum number of different data types that we will write to the
 // clipboard (plain text, RTF, HTML, image)
@@ -45,9 +43,6 @@ class Seat : public aura::client::FocusChangeObserver,
              public ui::PlatformEventObserver,
              public ui::EventHandler,
              public ui::ClipboardObserver,
-#if defined(OS_CHROMEOS)
-             public ash::ImeControllerImpl::Observer,
-#endif
              public DataSourceObserver {
  public:
   Seat();
@@ -67,9 +62,8 @@ class Seat : public aura::client::FocusChangeObserver,
     return pressed_keys_;
   }
 
-#if defined(OS_CHROMEOS)
-  const XkbTracker* xkb_tracker() const { return xkb_tracker_.get(); }
-#endif
+  // Returns current set of modifier flags.
+  int modifier_flags() const { return modifier_flags_; }
 
   // Returns physical code for the currently processing event.
   ui::DomCode physical_code_for_currently_processing_event() const {
@@ -108,12 +102,6 @@ class Seat : public aura::client::FocusChangeObserver,
   // Overridden from DataSourceObserver:
   void OnDataSourceDestroying(DataSource* source) override;
 
-#if defined(OS_CHROMEOS)
-  // Overridden from ash::ImeControllerImpl::Observer:
-  void OnCapsLockChanged(bool enabled) override;
-  void OnKeyboardLayoutNameChanged(const std::string& layout_name) override;
-#endif
-
   void set_physical_code_for_currently_processing_event_for_testing(
       ui::DomCode physical_code_for_currently_processing_event) {
     physical_code_for_currently_processing_event_ =
@@ -161,6 +149,7 @@ class Seat : public aura::client::FocusChangeObserver,
   // physical key press generated.
   base::flat_map<ui::DomCode, ui::DomCode> pressed_keys_;
   ui::DomCode physical_code_for_currently_processing_event_ = ui::DomCode::NONE;
+  int modifier_flags_ = 0;
 
   // Data source being used as a clipboard content.
   std::unique_ptr<ScopedDataSource> selection_source_;
@@ -176,7 +165,6 @@ class Seat : public aura::client::FocusChangeObserver,
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<UILockController> ui_lock_controller_;
-  std::unique_ptr<XkbTracker> xkb_tracker_;
 #endif  // defined(OS_CHROMEOS)
 
   base::WeakPtrFactory<Seat> weak_ptr_factory_{this};

components/exo/wayland/BUILD.gn

@@ -2,12 +2,19 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 import("//gpu/vulkan/features.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 import("//ui/ozone/ozone.gni")
 
+if (use_xkbcommon) {
+  pkg_config("xkbcommon") {
+    packages = [ "xkbcommon" ]
+  }
+}
+
 source_set("wayland") {
   sources = [
     "scoped_wl.cc",
@@ -129,6 +136,7 @@ source_set("wayland") {
   }
 
   if (use_xkbcommon) {
+    configs += [ ":xkbcommon" ]
     deps += [ "//ui/events/keycodes:xkb" ]
   }
 

components/exo/wayland/fuzzer/harness_unittest.cc

@@ -5,6 +5,7 @@
 #include "components/exo/wayland/fuzzer/harness.h"
 
 #include "base/files/scoped_temp_dir.h"
+#include "base/macros.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "components/exo/display.h"
@@ -12,36 +13,20 @@
 #include "components/exo/wayland/fuzzer/actions.pb.h"
 #include "components/exo/wayland/server.h"
 
-#if defined(OS_CHROMEOS)
-#include "components/exo/test/exo_test_base.h"
-#endif
-
 namespace exo {
 namespace wayland_fuzzer {
 namespace {
 
-// Use ExoTestBase on Chrome OS because Server starts to depends on ash::Shell,
-// which is unavailable on other platforms so then ExoTestBaseViews instead.
-using TestBase =
-#if defined(OS_CHROMEOS)
-    test::ExoTestBase
-#else
-    test::ExoTestBaseViews
-#endif
-    ;
-
-class WaylandFuzzerTest : public TestBase {
+class WaylandFuzzerTest : public test::ExoTestBaseViews {
  protected:
   WaylandFuzzerTest() = default;
-  WaylandFuzzerTest(const WaylandFuzzerTest&) = delete;
-  WaylandFuzzerTest& operator=(const WaylandFuzzerTest&) = delete;
   ~WaylandFuzzerTest() override = default;
 
   void SetUp() override {
     ASSERT_TRUE(xdg_temp_dir_.CreateUniqueTempDir());
     setenv("XDG_RUNTIME_DIR", xdg_temp_dir_.GetPath().MaybeAsASCII().c_str(),
            1 /* overwrite */);
-    TestBase::SetUp();
+    test::ExoTestBaseViews::SetUp();
     display_ = std::make_unique<exo::Display>();
     server_ = wayland::Server::Create(display_.get());
   }
@@ -49,12 +34,15 @@ class WaylandFuzzerTest : public TestBase {
   void TearDown() override {
     server_.reset();
     display_.reset();
-    TestBase::TearDown();
+    test::ExoTestBaseViews::TearDown();
   }
 
   base::ScopedTempDir xdg_temp_dir_;
   std::unique_ptr<exo::Display> display_;
   std::unique_ptr<wayland::Server> server_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WaylandFuzzerTest);
 };
 
 void RunHarness(Harness* harness, base::WaitableEvent* event) {

components/exo/wayland/server_unittest.cc

@@ -20,10 +20,6 @@
 #include "components/exo/test/exo_test_base_views.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-#if defined(OS_CHROMEOS)
-#include "components/exo/test/exo_test_base.h"
-#endif
-
 namespace exo {
 namespace wayland {
 namespace {
@@ -35,32 +31,22 @@ std::string GetUniqueSocketName() {
                             g_next_socket_id.GetNext());
 }
 
-// Use ExoTestBase on Chrome OS because Server starts to depends on ash::Shell,
-// which is unavailable on other platforms so then ExoTestBaseViews instead.
-using TestBase =
-#if defined(OS_CHROMEOS)
-    test::ExoTestBase
-#else
-    test::ExoTestBaseViews
-#endif
-    ;
-
-class ServerTest : public TestBase {
+class ServerTest : public test::ExoTestBaseViews {
  public:
-  ServerTest() = default;
-  ServerTest(const ServerTest&) = delete;
-  ServerTest& operator=(const ServerTest&) = delete;
-  ~ServerTest() override = default;
+  ServerTest() {}
+  ~ServerTest() override {}
 
   void SetUp() override {
     ASSERT_TRUE(xdg_temp_dir_.CreateUniqueTempDir());
     setenv("XDG_RUNTIME_DIR", xdg_temp_dir_.GetPath().MaybeAsASCII().c_str(),
            1 /* overwrite */);
-    TestBase::SetUp();
+    test::ExoTestBaseViews::SetUp();
   }
 
  private:
   base::ScopedTempDir xdg_temp_dir_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServerTest);
 };
 
 TEST_F(ServerTest, AddSocket) {

components/exo/wayland/wayland_keyboard_delegate.cc

@@ -10,13 +10,11 @@
 #include <wayland-server-protocol-core.h>
 
 #include "base/containers/flat_map.h"
+#include "components/exo/keyboard_modifiers.h"
 #include "components/exo/wayland/serial_tracker.h"
+#include "components/exo/xkb_tracker.h"
 #include "ui/events/keycodes/dom/dom_code.h"
 
-#if BUILDFLAG(USE_XKBCOMMON)
-#include <xkbcommon/xkbcommon.h>
-#endif
-
 namespace exo {
 namespace wayland {
 
@@ -24,7 +22,9 @@ namespace wayland {
 
 WaylandKeyboardDelegate::WaylandKeyboardDelegate(wl_resource* keyboard_resource,
                                                  SerialTracker* serial_tracker)
-    : keyboard_resource_(keyboard_resource), serial_tracker_(serial_tracker) {}
+    : keyboard_resource_(keyboard_resource),
+      serial_tracker_(serial_tracker),
+      xkb_tracker_(std::make_unique<XkbTracker>()) {}
 
 WaylandKeyboardDelegate::~WaylandKeyboardDelegate() = default;
 
@@ -88,9 +88,11 @@ uint32_t WaylandKeyboardDelegate::OnKeyboardKey(base::TimeTicks time_stamp,
   return serial;
 }
 
-void WaylandKeyboardDelegate::OnKeyboardModifiers(
-    const KeyboardModifiers& modifiers) {
+void WaylandKeyboardDelegate::OnKeyboardModifiers(int modifier_flags) {
+  xkb_tracker_->UpdateKeyboardModifiers(modifier_flags);
+
   // Send the update only when they're different.
+  const KeyboardModifiers modifiers = xkb_tracker_->GetModifiers();
   if (current_modifiers_ == modifiers)
     return;
   current_modifiers_ = modifiers;
@@ -98,23 +100,9 @@ void WaylandKeyboardDelegate::OnKeyboardModifiers(
 }
 
 void WaylandKeyboardDelegate::OnKeyboardLayoutUpdated(
-    base::StringPiece keymap) {
-  // Sent the content of |keymap| with trailing '\0' termination via shared
-  // memory.
-  base::UnsafeSharedMemoryRegion shared_keymap_region =
-      base::UnsafeSharedMemoryRegion::Create(keymap.size() + 1);
-  base::WritableSharedMemoryMapping shared_keymap = shared_keymap_region.Map();
-  base::subtle::PlatformSharedMemoryRegion platform_shared_keymap =
-      base::UnsafeSharedMemoryRegion::TakeHandleForSerialization(
-          std::move(shared_keymap_region));
-  DCHECK(shared_keymap.IsValid());
-
-  std::memcpy(shared_keymap.memory(), keymap.data(), keymap.size());
-  static_cast<uint8_t*>(shared_keymap.memory())[keymap.size()] = '\0';
-  wl_keyboard_send_keymap(keyboard_resource_, WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1,
-                          platform_shared_keymap.GetPlatformHandle().fd,
-                          keymap.size() + 1);
-  wl_client_flush(client());
+    const std::string& layout_name) {
+  xkb_tracker_->UpdateKeyboardLayout(layout_name);
+  SendLayout();
 }
 
 uint32_t WaylandKeyboardDelegate::DomCodeToKey(ui::DomCode code) const {
@@ -136,6 +124,25 @@ void WaylandKeyboardDelegate::SendKeyboardModifiers() {
   wl_client_flush(client());
 }
 
+void WaylandKeyboardDelegate::SendLayout() {
+  auto keymap = xkb_tracker_->GetKeymap();
+  size_t keymap_size = strlen(keymap.get()) + 1;
+
+  base::UnsafeSharedMemoryRegion shared_keymap_region =
+      base::UnsafeSharedMemoryRegion::Create(keymap_size);
+  base::WritableSharedMemoryMapping shared_keymap = shared_keymap_region.Map();
+  base::subtle::PlatformSharedMemoryRegion platform_shared_keymap =
+      base::UnsafeSharedMemoryRegion::TakeHandleForSerialization(
+          std::move(shared_keymap_region));
+  DCHECK(shared_keymap.IsValid());
+
+  std::memcpy(shared_keymap.memory(), keymap.get(), keymap_size);
+  wl_keyboard_send_keymap(keyboard_resource_, WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1,
+                          platform_shared_keymap.GetPlatformHandle().fd,
+                          keymap_size);
+  wl_client_flush(client());
+}
+
 // Convert from ChromeOS's key repeat interval to Wayland's key repeat rate.
 // For example, an interval of 500ms is a rate of 1000/500 = 2 Hz.
 //

components/exo/wayland/wayland_keyboard_delegate.h

@@ -16,10 +16,18 @@
 #include "ui/base/buildflags.h"
 #include "ui/events/keycodes/dom/keycode_converter.h"
 
+#if BUILDFLAG(USE_XKBCOMMON)
+#include <xkbcommon/xkbcommon.h>
+#include "ui/events/keycodes/scoped_xkb.h"  // nogncheck
+#endif
+
 struct wl_client;
 struct wl_resource;
 
 namespace exo {
+
+class XkbTracker;
+
 namespace wayland {
 class SerialTracker;
 
@@ -42,11 +50,11 @@ class WaylandKeyboardDelegate : public WaylandInputDelegate,
   uint32_t OnKeyboardKey(base::TimeTicks time_stamp,
                          ui::DomCode key,
                          bool pressed) override;
-  void OnKeyboardModifiers(const KeyboardModifiers& modifiers) override;
+  void OnKeyboardModifiers(int modifier_flags) override;
   void OnKeyRepeatSettingsChanged(bool enabled,
                                   base::TimeDelta delay,
                                   base::TimeDelta interval) override;
-  void OnKeyboardLayoutUpdated(base::StringPiece keymap) override;
+  void OnKeyboardLayoutUpdated(const std::string& layout_name) override;
 
  private:
   // Returns the corresponding key given a dom code.
@@ -55,6 +63,9 @@ class WaylandKeyboardDelegate : public WaylandInputDelegate,
   // Sends the current modifiers to the client.
   void SendKeyboardModifiers();
 
+  // Send the current keyboard layout to the client.
+  void SendLayout();
+
   // The client who own this keyboard instance.
   wl_client* client() const;
 
@@ -64,6 +75,10 @@ class WaylandKeyboardDelegate : public WaylandInputDelegate,
   // Owned by Server, which always outlives this delegate.
   SerialTracker* const serial_tracker_;
 
+  // TODO(hidehiko): Move this to the server in order to share it with
+  // zwp_text_input.
+  std::unique_ptr<XkbTracker> xkb_tracker_;
+
   // Tracks the latest modifiers.
   KeyboardModifiers current_modifiers_{};