The following tests fail in the content_browsertests step on eight trybots:

  DumpAccessibilityTreeTest.AccessibilityIframeCoordinates
  DumpAccessibilityTreeTest.AccessibilityIframeCoordinatesCrossProcess
  DumpAccessibilityTreeTest.AccessibilityIframeTransformScrolled

On some bots the same test is run by other recipe steps, such as:

  mus_content_browsertests
  network_service_content_browsertests
  site_per_process_content_browsertests
  viz_content_browsertests

The affected bots are:

https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_rel_ng/620275
https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_asan_rel_ng/521864
https://ci.chromium.org/buildbot/tryserver.chromium.linux/linux_chromium_tsan_rel_ng/227446
https://ci.chromium.org/buildbot/tryserver.chromium.linux/cast_shell_linux/517283
https://ci.chromium.org/buildbot/tryserver.chromium.chromiumos/linux-chromeos-rel/34722
https://ci.chromium.org/buildbot/tryserver.chromium.mac/mac_chromium_rel_ng/623932
https://ci.chromium.org/buildbot/tryserver.chromium.win/win10_chromium_x64_rel_ng/58124
https://ci.chromium.org/buildbot/tryserver.chromium.win/win7_chromium_rel_ng/76819

The output includes:

../../content/browser/accessibility/dump_accessibility_browsertest_base.cc:371: Failure
Value of: is_different
  Actual: true
Expected: false
[16974:16974:0109/122951.027493:ERROR:dump_accessibility_browsertest_base.cc(396)] Diff:
* Line Expected
- ---- --------
     1 rootWebArea location=(0, 0) scrollX=0 scrollY=0
     2 ++genericContainer location=(0, 0) size=(300, 150)
     3 ++++button location=(25, 25) size=(250, 50) unclippedSize=(250, 50) name='Button'
     4 ++genericContainer location=(0, 150) size=(300, 150)
     5 ++++button location=(25, 175) size=(250, 50) unclippedSize=(250, 50) name='Button'
     6 ++genericContainer location=(0, 300) size=(300, 150)
     7 ++++iframe location=(0, 300) size=(300, 100) unclippedSize=(300, 100)
     8 ++++++rootWebArea location=(0, 0) size=(300, 100) unclippedSize=(300, 100) scrollX=0 scrollY=0
     9 ++++++++genericContainer location=(0, 0) size=(300, 100) unclippedSize=(300, 100)
    10 ++++++++++button location=(25, 25) size=(250, 50) unclippedSize=(250, 50) name='Ordinary Button'
    11 ++genericContainer location=(0, 450) size=(300, 150)
    12 ++++iframe location=(0, 450) size=(150, 50)
    13 ++++++rootWebArea location=(0, 0) size=(150, 50) scrollX=150 scrollY=50
*   14 ++++++++genericContainer location=(0, 0) size=(300, 100) unclippedLocation=(-150, 400) unclippedSize=(300, 100)
*   15 ++++++++++button location=(25, 25) size=(250, 50) unclippedLocation=(-125, 425) unclippedSize=(250, 50) name='Scrolled Button'
    16 <-- End-of-file -->
    17 <-- End-of-file -->
Actual
------
rootWebArea location=(0, 0) scrollX=0 scrollY=0
++genericContainer location=(0, 0) size=(300, 150)
++++button location=(25, 25) size=(250, 50) unclippedSize=(250, 50) name='Button'
++genericContainer location=(0, 150) size=(300, 150)
++++button location=(25, 175) size=(250, 50) unclippedSize=(250, 50) name='Button'
++genericContainer location=(0, 300) size=(300, 150)
++++iframe location=(0, 300) size=(300, 100) unclippedSize=(300, 100)
++++++rootWebArea location=(0, 0) size=(300, 100) unclippedSize=(300, 100) scrollX=0 scrollY=0
++++++++genericContainer location=(0, 0) size=(300, 100) unclippedSize=(300, 100)
++++++++++button location=(25, 25) size=(250, 50) unclippedSize=(250, 50) name='Ordinary Button'
++genericContainer location=(0, 450) size=(300, 150)
++++iframe location=(0, 450) size=(150, 50)
++++++rootWebArea location=(0, 0) size=(150, 50) scrollX=150 scrollY=50
++++++++genericContainer location=(-150, -50) size=(300, 100) unclippedSize=(300, 100)
++++++++++button location=(-125, -25) size=(250, 50) unclippedSize=(250, 50) name='Scrolled Button'
<-- End-of-file -->