Telemetry: Disable TabTest:testTabIsAlive on Android due to its failure

tools/telemetry/telemetry/core/tab_unittest.py

 # Copyright 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import logging
 import tempfile
 
 from telemetry import decorators
 from telemetry.image_processing import image_util
 from telemetry.image_processing import rgba_color
@@ skipping 146 matching lines @@
     renderer_thread = timeline_model.GetRendererThreadFromTabId(
         second_tab.id)
     second_tab_markers = [
         renderer_thread.IterAllSlicesOfName('second-tab-marker')]
     self.assertEquals(1, len(second_tab_markers))
 
     # Third tab wasn't available when we start tracing, so there is no
     # renderer_thread corresponding to it in the the trace.
     self.assertIs(None, timeline_model.GetRendererThreadFromTabId(third_tab.id))
 
+  @decorators.Disabled('android') # https://crbug.com/463933
   def testTabIsAlive(self):
     self.assertEquals(self._tab.url, 'about:blank')
     self.assertTrue(self._tab.IsAlive())
 
     self._tab.Navigate(self.UrlOfUnittestFile('blank.html'))
     self.assertTrue(self._tab.IsAlive())
 
     self.assertRaises(exceptions.DevtoolsTargetCrashException,
         lambda: self._tab.Navigate(self.UrlOfUnittestFile('chrome://crash')))
     self.assertFalse(self._tab.IsAlive())
@@ skipping 18 matching lines @@
     assert screenshot is not None
     image_util.GetPixelColor(
         screenshot, 0 * pixel_ratio, 0 * pixel_ratio).AssertIsRGB(
             0, 255, 0, tolerance=2)
     image_util.GetPixelColor(
         screenshot, 31 * pixel_ratio, 31 * pixel_ratio).AssertIsRGB(
             0, 255, 0, tolerance=2)
     image_util.GetPixelColor(
         screenshot, 32 * pixel_ratio, 32 * pixel_ratio).AssertIsRGB(
             255, 255, 255, tolerance=2)