Revert "ozone/wayland: gracefully shutdown the browser on protocol error."

This reverts commit fa06bf45.

Reason for revert: Believe this introduces flakiness and failures on lacros. See https://bugs.chromium.org/p/chromium/issues/detail?id=1129425

Original change's description:
> ozone/wayland: gracefully shutdown the browser on protocol error.
> 
> Wayland may disconnect the client if it hits an unrecoverable
> error. That is, it prints an error message and client cannot
> do anything about that after that except shutting itself down.
> 
> Thus, while watching the display fd, always check for errors. If
> a protocol error is set, trigger |shutdown_cb| and also stop
> watching the fd.
> 
> Bug: 1127278
> Change-Id: Ie324af93d455c0c83f8e75cdecfafe2254da1972
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404931
> Commit-Queue: Maksim Sisov (GMT+3) <msisov@igalia.com>
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#807775}

TBR=rjkroege@chromium.org,msisov@igalia.com

Change-Id: Ie1cfa657b34930ebc6e568c1d422dbfae910197a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1127278
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416884Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Joshua Pawlicki <waffles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808009}

ui/ozone/platform/wayland/host/wayland_connection.cc

@@ -131,10 +131,6 @@ void WaylandConnection::ScheduleFlush() {
   }
 }
 
-void WaylandConnection::SetShutdownCb(base::OnceCallback<void()> shutdown_cb) {
-  event_source()->SetShutdownCb(std::move(shutdown_cb));
-}
-
 void WaylandConnection::SetCursorBitmap(const std::vector<SkBitmap>& bitmaps,
                                         const gfx::Point& location) {
   if (!cursor_)

ui/ozone/platform/wayland/host/wayland_connection.h

@@ -56,10 +56,6 @@ class WaylandConnection {
   // Schedules a flush of the Wayland connection.
   void ScheduleFlush();
 
-  // Sets a callback that that shutdowns the browser in case of unrecoverable
-  // error. Called by WaylandEventWatcher.
-  void SetShutdownCb(base::OnceCallback<void()> shutdown_cb);
-
   wl_display* display() const { return display_.get(); }
   wl_compositor* compositor() const { return compositor_.get(); }
   uint32_t compositor_version() const { return compositor_version_; }

ui/ozone/platform/wayland/host/wayland_event_source.cc

@@ -67,10 +67,6 @@ WaylandEventSource::WaylandEventSource(wl_display* display,
 
 WaylandEventSource::~WaylandEventSource() = default;
 
-void WaylandEventSource::SetShutdownCb(base::OnceCallback<void()> shutdown_cb) {
-  event_watcher_->SetShutdownCb(std::move(shutdown_cb));
-}
-
 bool WaylandEventSource::StartProcessingEvents() {
   return event_watcher_->StartProcessingEvents();
 }

ui/ozone/platform/wayland/host/wayland_event_source.h

@@ -61,10 +61,6 @@ class WaylandEventSource : public PlatformEventSource,
 
   int keyboard_modifiers() const { return keyboard_modifiers_; }
 
-  // Sets a callback that that shutdowns the browser in case of unrecoverable
-  // error. Called by WaylandEventWatcher.
-  void SetShutdownCb(base::OnceCallback<void()> shutdown_cb);
-
   // Starts polling for events from the wayland connection file descriptor.
   // This method assumes connection is already estabilished and input objects
   // are already bound and properly initialized.

ui/ozone/platform/wayland/host/wayland_event_watcher.cc

@@ -21,12 +21,6 @@ WaylandEventWatcher::~WaylandEventWatcher() {
   StopProcessingEvents();
 }
 
-void WaylandEventWatcher::SetShutdownCb(
-    base::OnceCallback<void()> shutdown_cb) {
-  DCHECK(shutdown_cb_.is_null());
-  shutdown_cb_ = std::move(shutdown_cb);
-}
-
 bool WaylandEventWatcher::StartProcessingEvents() {
   DCHECK(display_);
   if (watching_)
@@ -48,11 +42,6 @@ bool WaylandEventWatcher::StopProcessingEvents() {
 }
 
 void WaylandEventWatcher::OnFileCanReadWithoutBlocking(int fd) {
-  if (!CheckForErrors()) {
-    StopProcessingEvents();
-    return;
-  }
-
   if (prepared_) {
     prepared_ = false;
     if (wl_display_read_events(display_) == -1)
@@ -113,15 +102,4 @@ void WaylandEventWatcher::MaybePrepareReadQueue() {
   wl_display_dispatch_pending(display_);
 }
 
-bool WaylandEventWatcher::CheckForErrors() {
-  int err = wl_display_get_error(display_);
-  if (err == EPROTO) {
-    // This can be null in tests.
-    if (!shutdown_cb_.is_null())
-      std::move(shutdown_cb_).Run();
-    return false;
-  }
-  return true;
-}
-
 }  // namespace ui

ui/ozone/platform/wayland/host/wayland_event_watcher.h

@@ -5,7 +5,6 @@
 #ifndef UI_OZONE_PLATFORM_WAYLAND_HOST_WAYLAND_EVENT_WATCHER_H_
 #define UI_OZONE_PLATFORM_WAYLAND_HOST_WAYLAND_EVENT_WATCHER_H_
 
-#include "base/callback.h"
 #include "base/message_loop/message_pump_for_ui.h"
 #include "base/message_loop/watchable_io_message_pump_posix.h"
 
@@ -24,10 +23,6 @@ class WaylandEventWatcher : public base::MessagePumpForUI::FdWatcher {
   WaylandEventWatcher& operator=(const WaylandEventWatcher&) = delete;
   ~WaylandEventWatcher() override;
 
-  // Sets a callback that that shutdowns the browser in case of unrecoverable
-  // error. Can only be set once.
-  void SetShutdownCb(base::OnceCallback<void()> shutdown_cb);
-
   // Starts polling for events from the wayland connection file descriptor.
   // This method assumes connection is already estabilished and input objects
   // are already bound and properly initialized.
@@ -44,18 +39,12 @@ class WaylandEventWatcher : public base::MessagePumpForUI::FdWatcher {
   bool StartWatchingFd(base::WatchableIOMessagePumpPosix::Mode mode);
   void MaybePrepareReadQueue();
 
-  // Checks if |display_| has any error set. If so, |shutdown_cb_| is executed
-  // and false is returned.
-  bool CheckForErrors();
-
   base::MessagePumpForUI::FdWatchController controller_;
 
   wl_display* const display_;  // Owned by WaylandConnection.
 
   bool watching_ = false;
   bool prepared_ = false;
-
-  base::OnceCallback<void()> shutdown_cb_;
 };
 
 }  // namespace ui

ui/ozone/platform/wayland/ozone_platform_wayland.cc

@@ -258,12 +258,6 @@ class OzonePlatformWayland : public OzonePlatform {
     buffer_manager_->AddBindingWaylandBufferManagerGpu(std::move(receiver));
   }
 
-  void PostMainMessageLoopStart(
-      base::OnceCallback<void()> shutdown_cb) override {
-    DCHECK(connection_);
-    connection_->SetShutdownCb(std::move(shutdown_cb));
-  }
-
  private:
 #if BUILDFLAG(USE_XKBCOMMON)
   XkbEvdevCodes xkb_evdev_code_converter_;