DumpAccessibilityTreeTest.AccessibilityAriaTextboxWithRichText started failing on most of the Android bots.

First failing build: https://uberchromegw.corp.google.com/i/chromium.android/builders/KitKat%20Tablet%20Tester/builds/3490

Likely culprit CL: https://codereview.chromium.org/1821723002 ("Exposed the children of elements with role textbox in order to make rich text information available to Windows screen readers.")

Failure log:

https://uberchromegw.corp.google.com/i/chromium.android/builders/KitKat%20Tablet%20Tester/builds/3490/steps/content_browsertests/logs/stdio

I  800.458s run_tests_on_device(057ccb85)  [ RUN      ] DumpAccessibilityTreeTest.AccessibilityAriaTextboxWithRichText
I  800.458s run_tests_on_device(057ccb85)  [WARNING:dns_config_service_posix.cc(306)] Failed to read DnsConfig.
I  800.458s run_tests_on_device(057ccb85)  [ERROR:devtools_http_handler.cc(229)] Cannot start http server for devtools. Stop devtools.
I  800.458s run_tests_on_device(057ccb85)  [ERROR:shell.cc(302)] Error: Instance: exe:chrome attempting to register an instance for a process it created for target: exe:chrome_renderer without the mojo:shell{client_process} capability class.
I  800.458s run_tests_on_device(057ccb85)  [ERROR:layer_tree_host_impl.cc(2205)] Forcing zero-copy tile initialization as worker context is missing
I  800.458s run_tests_on_device(057ccb85)  [INFO:dump_accessibility_browsertest_base.cc(200)] Testing: /storage/emulated/0/content/test/data/accessibility/aria/aria-textbox-with-rich-text.html (native accessibility tree for this platform)
I  800.458s run_tests_on_device(057ccb85)  [WARNING:simple_synchronous_entry.cc(908)] Could not open platform files for entry.
I  800.458s run_tests_on_device(057ccb85)  ../../content/browser/accessibility/dump_accessibility_browsertest_base.cc:339: Failure
I  800.458s run_tests_on_device(057ccb85)  Value of: is_different
I  800.458s run_tests_on_device(057ccb85)    Actual: true
I  800.458s run_tests_on_device(057ccb85)  Expected: false
I  800.458s run_tests_on_device(057ccb85)  [ERROR:dump_accessibility_browsertest_base.cc(364)] Diff:
I  800.458s run_tests_on_device(057ccb85)  * Line Expected
I  800.458s run_tests_on_device(057ccb85)  - ---- --------
I  800.458s run_tests_on_device(057ccb85)       1 android.webkit.WebView focusable scrollable
I  800.458s run_tests_on_device(057ccb85)       2 ++android.widget.EditText clickable editable_text focusable focused multiline name='TextBox1
I  800.458s run_tests_on_device(057ccb85)  *    3 ' text_change_added_count=9
I  800.458s run_tests_on_device(057ccb85)       4 ++android.widget.EditText clickable editable_text focusable multiline name='TextBox2
I  800.458s run_tests_on_device(057ccb85)  *    5 Some text.' text_change_added_count=19
I  800.459s run_tests_on_device(057ccb85)       6 <-- End-of-file -->
I  800.459s run_tests_on_device(057ccb85)  
I  800.459s run_tests_on_device(057ccb85)  Actual
I  800.459s run_tests_on_device(057ccb85)  ------
I  800.459s run_tests_on_device(057ccb85)  android.webkit.WebView focusable scrollable
I  800.459s run_tests_on_device(057ccb85)  ++android.widget.EditText clickable editable_text focusable focused multiline name='TextBox1
I  800.459s run_tests_on_device(057ccb85)  ' text_change_added_count=10
I  800.459s run_tests_on_device(057ccb85)  ++android.widget.EditText clickable editable_text focusable multiline name='TextBox2
I  800.459s run_tests_on_device(057ccb85)  Some text.' text_change_added_count=20
I  800.459s run_tests_on_device(057ccb85)  <-- End-of-file -->
I  800.459s run_tests_on_device(057ccb85)  [  FAILED  ] DumpAccessibilityTreeTest.AccessibilityAriaTextboxWithRichText, where TypeParam =  and GetParam() =  (960 ms)
I  800.459s run_tests_on_device(057ccb85)  [----------] 1 test from DumpAccessibilityTreeTest (960 ms total)