These tests fail in the browser_tests, mus_browser_tests, and site_per_process_browser_tests steps on some bots:

  PDFExtensionTest.ContextMenuCoordinates
  PDFExtensionTest.EnsureCrossOriginRepliesBlocked
  PDFExtensionTest.PdfAccessibilityInIframe
  PDFExtensionTest.TabTitleWithEmbeddedPdf

Bot links:

  https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_rel_ng/620275
    (ContextMenuCoordinates, EnsureCrossOriginRepliesBlocked, TabTitleWithEmbeddedPdf)

  https://ci.chromium.org/buildbot/tryserver.chromium.chromiumos/linux-chromeos-rel/34722
    (ContextMenuCoordinates, PdfAccessibilityInIframe)

  https://ci.chromium.org/buildbot/tryserver.chromium.mac/mac_chromium_rel_ng/623932
    (PdfAccessibilityInIframe)

  https://ci.chromium.org/buildbot/tryserver.chromium.win/win10_chromium_x64_rel_ng/58124
    (ContextMenuCoordinates)

  https://ci.chromium.org/buildbot/tryserver.chromium.win/win7_chromium_rel_ng/76819
    (PdfAccessibilityInIframe, EnsureCrossOriginRepliesBlocked)

The output includes:

[1:1:0109/123116.535460:FATAL:PaintLayer.h(338)] Check failed: !needs_descendant_dependent_flags_update_.
#0 0x0000053e8bac base::debug::StackTrace::StackTrace()
#1 0x00000540913c logging::LogMessage::~LogMessage()
#2 0x000008edda75 blink::PaintLayer::SubtreeIsInvisible()
#3 0x00000909f746 blink::LocalFrameView::InvalidateViewportConstrainedObjects()
#4 0x0000097a942a blink::PaintLayerScrollableArea::InvalidatePaintForScrollOffsetChange()
#5 0x0000097a86b9 blink::PaintLayerScrollableArea::UpdateScrollOffset()
#6 0x000008a397be blink::ScrollableArea::ScrollOffsetChanged()
#7 0x000008a3d0c0 blink::ProgrammaticScrollAnimator::ScrollToOffsetWithoutAnimation()
#8 0x000008a396ab blink::ScrollableArea::SetScrollOffset()
#9 0x00000907c990 blink::LocalDOMWindow::scrollTo()
#10 0x0000087d89bc blink::V8Window::scrollToMethodCallback()
#11 0x000004724d82 v8::internal::FunctionCallbackArguments::Call()
#12 0x00000480a8d5 v8::internal::(anonymous namespace)::HandleApiCallHelper<>()
#13 0x0000048089c9 v8::internal::Builtin_Impl_HandleApiCall()
#14 0x00000480840d v8::internal::Builtin_HandleApiCall()
#15 0x22ba49604384 <unknown>