The 1st crash is
[19872:19872:0605/162225.884250:FATAL:display_finder.cc(42)] Check failed: !displays.empty(). 
#0 0x7f762e7932cc base::debug::StackTrace::StackTrace()
#1 0x7f762e6dd6db logging::LogMessage::~LogMessage()
#2 0x7f762a3ba833 display::FindDisplayWithBiggestIntersection()
#3 0x7f762a3c46c5 display::ScreenBase::GetDisplayMatching()
#4 0x562833a01d99 WindowSizer::DetermineWindowBoundsAndShowState()
#5 0x562833a01c1e WindowSizer::GetBrowserWindowBoundsAndShowState()
#6 0x562833a03332 chrome::GetSavedWindowBoundsAndShowState()
#7 0x562833abe727 BrowserFrame::InitBrowserFrame()
#8 0x562833afeae5 BrowserWindow::CreateBrowserWindow()
#9 0x562833910ce4 Browser::Browser()
#10 0x562832b00607 SessionRestoreImpl::CreateRestoredBrowser()
#11 0x562832affcbe SessionRestoreImpl::ProcessSessionWindows()
#12 0x562832afe40a SessionRestoreImpl::Restore()
#13 0x562832afded5 SessionRestore::RestoreSession()
#14 0x562833951aab StartupBrowserCreatorImpl::RestoreOrCreateBrowser()
#15 0x562833950bf5 StartupBrowserCreatorImpl::DetermineURLsAndLaunch()
#16 0x5628339505dd StartupBrowserCreatorImpl::Launch()

The 2nd crash is
[20430:20430:0605/162915.735497:FATAL:x11_window_base.cc(119)] Check failed: !bounds_.size().IsEmpty(). 
#0 0x7f6650ba96dc base::debug::StackTrace::StackTrace()
#1 0x7f6650af16db logging::LogMessage::~LogMessage()
#2 0x7f66406a329c ui::X11WindowBase::Create()
#3 0x7f66406a3200 ui::X11WindowBase::X11WindowBase()
#4 0x7f66435b25ce ui::X11WindowOzone::X11WindowOzone()
#5 0x7f66435b133c ui::(anonymous namespace)::OzonePlatformX11::CreatePlatformWindow()
#6 0x7f66435a15b3 ui::(anonymous namespace)::OzonePlatformHeadless::CreatePlatformWindowWithProperties()
#7 0x7f664c5348ae aura::WindowTreeHostPlatform::CreateAndSetPlatformWindowWithProperties()
#8 0x7f664b61b307 views::DesktopWindowTreeHostPlatform::Init()
#9 0x7f664b612f99 views::DesktopNativeWidgetAura::InitNativeWidget()
#10 0x7f664b5f7d07 views::Widget::Init()

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/490c27babbe440762253c71c8ddc2438d3814d0e

commit 490c27babbe440762253c71c8ddc2438d3814d0e
Author: Julie Jeongeun Kim <jkim@igalia.com>
Date: Sat Aug 11 03:37:47 2018

Deliver bounds information to CreateTooltipWidget

When 'CreateTooltipWidget' creates 'Widget' for tooltip and
initializes it, it needs its bounds at InitParams. If it
doesn't have the bounds information, some platform widgets
get crashed and DesktopWindowTreeHostX11 keeps
|sanitized_params| to avoid this case.

This patch delivers the bounds for the tooltip widget and
adds DCHECK to find what causes the empty bounds.

Bug: 849585
Change-Id: I3de067a917e4343bab642c3a1b13434b6cfaeee0
Reviewed-on: https://chromium-review.googlesource.com/1086820
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#582426}
[modify] https://crrev.com/490c27babbe440762253c71c8ddc2438d3814d0e/ui/platform_window/x11/x11_window_base.cc
[modify] https://crrev.com/490c27babbe440762253c71c8ddc2438d3814d0e/ui/views/corewm/tooltip_aura.cc
[modify] https://crrev.com/490c27babbe440762253c71c8ddc2438d3814d0e/ui/views/corewm/tooltip_aura.h

#0 0x7fc168e7d4bd base::debug::StackTrace::StackTrace()
#1 0x7fc168b4f75a base::debug::StackTrace::StackTrace()
#2 0x7fc168e7cf0a base::debug::(anonymous namespace)::StackDumpSignalHandler()
#3 0x7fc13d9f3150 <unknown>
#4 0x7fc15d358bd6 ui::InputMethodAuraLinux::InputMethodAuraLinux()
#5 0x7fc15d356eae ui::CreateInputMethod()
#6 0x7fc15a6e20b1 aura::WindowTreeHost::GetInputMethod()
#7 0x7fc1542553c4 views::DesktopNativeWidgetAura::GetInputMethod()
#8 0x7fc1541f5a53 views::Widget::GetInputMethod()
#9 0x7fc15420e1ce views::Widget::OnNativeWidgetSizeChanged()
#10 0x7fc154258636 views::DesktopNativeWidgetAura::OnHostResized()
#11 0x7fc154252b95 views::DesktopNativeWidgetAura::InitNativeWidget()
#12 0x555bc80d5bcf DesktopBrowserFrameAura::InitNativeWidget()
#13 0x7fc154209e5a views::Widget::Init()
#14 0x555bc7e77290 BrowserFrame::InitBrowserFrame()
#15 0x555bc7e94bb1 BrowserWindow::CreateBrowserWindow()
#16 0x555bc7a939a0 (anonymous namespace)::CreateBrowserWindow()
#17 0x555bc7a92e4d Browser::Browser()
#18 0x555bc440156e SessionRestoreImpl::CreateRestoredBrowser()
#19 0x555bc44001d8 SessionRestoreImpl::ProcessSessionWindows()
#20 0x555bc43ff02e SessionRestoreImpl::ProcessSessionWindowsAndNotify()
#21 0x555bc43f9326 SessionRestoreImpl::Restore()
#22 0x555bc43d413c SessionRestore::RestoreSession()
#23 0x555bc7b5c312 StartupBrowserCreatorImpl::RestoreOrCreateBrowser()
#24 0x555bc7b58741 StartupBrowserCreatorImpl::DetermineURLsAndLaunch()
#25 0x555bc7b53d82 StartupBrowserCreatorImpl::Launch()
#26 0x555bc7b52440 StartupBrowserCreator::LaunchBrowser()
#27 0x555bc7b55c7a StartupBrowserCreator::ProcessLastOpenedProfiles()
#28 0x555bc7b551c5 StartupBrowserCreator::LaunchBrowserForLastProfiles()
#29 0x555bc7b52047 StartupBrowserCreator::ProcessCmdLineImpl()
#30 0x555bc7b50302 StartupBrowserCreator::Start()

***UI Mass Triage ***

As we discussed it on the CL[1], we need the implementation that provides an impl for LinuxUI.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1314509