Disable a few more unittests temporarily.

tools/telemetry/telemetry/core/tab_unittest.py

Index: tools/telemetry/telemetry/core/tab_unittest.py
diff --git a/tools/telemetry/telemetry/core/tab_unittest.py b/tools/telemetry/telemetry/core/tab_unittest.py
index 0c02780125c199109eb932789593ff0dc8c23c6c..95730322d89642164b6e392d11665c1b21e4ea22 100644
--- a/tools/telemetry/telemetry/core/tab_unittest.py
+++ b/tools/telemetry/telemetry/core/tab_unittest.py
@@ -102,6 +102,7 @@ class TabTest(tab_test_case.TabTestCase):
     finally:
       self._tab.browser._platform_backend = original_platform_backend
 
+  @benchmark.Disabled('chromeos') # crbug.com/412713.
   def testHighlight(self):
     self.assertEquals(self._tab.url, 'about:blank')
     options = tracing_options.TracingOptions()
@@ -122,6 +123,7 @@ class TabTest(tab_test_case.TabTestCase):
     self.assertTrue(found_video_start_event)
 
   @benchmark.Enabled('has tabs')
+  @benchmark.Disabled('chromeos') # crbug.com/412713.
   def testGetRendererThreadFromTabId(self):
     self.assertEquals(self._tab.url, 'about:blank')
     # Create 3 tabs. The third tab is closed before we call