Try disabling GPU watchdog in WebGL conformance tests.

content/test/gpu/gpu_tests/webgl_conformance_integration_test.py

 # Copyright 2016 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 os
 
 from gpu_tests import gpu_integration_test
 from gpu_tests import path_util
 from gpu_tests import webgl_conformance_expectations
 from gpu_tests import webgl2_conformance_expectations
@@ skipping 234 matching lines @@
     assert cls._webgl_version == 1 or cls._webgl_version == 2
     browser_options = cls._finder_options.browser_options
     # --test-type=gpu is used only to suppress the "Google API Keys are missing"
     # infobar, which causes flakiness in tests.
     browser_options.AppendExtraBrowserArgs([
         '--disable-gesture-requirement-for-media-playback',
         '--disable-domain-blocking-for-3d-apis',
         '--disable-gpu-process-crash-limit',
         '--js-flags=--expose-gc',
         '--test-type=gpu',
-        '--enable-experimental-canvas-features'
+        '--enable-experimental-canvas-features',
+        # Try disabling the GPU watchdog to see if this affects the
+        # intermittent GPU process hangs that have been seen on the
+        # waterfall. crbug.com/596622 crbug.com/609252
+        '--disable-gpu-watchdog'
     ])
     if cls._webgl_version == 2:
       browser_options.AppendExtraBrowserArgs([
         '--enable-unsafe-es3-apis',
       ])
     browser = browser_finder.FindBrowser(browser_options.finder_options)
     if (browser.target_os.startswith('android') and
       browser.browser_type == 'android-webview-shell'):
       # TODO(kbr): this is overly broad. We'd like to do this only on
       # Nexus 9. It'll go away shortly anyway. crbug.com/499928
@@ skipping 95 matching lines @@
           # We only check min-version >= 2.0.0 for the top level list.
           test_paths += cls._ParseTests(
               include_path, version, webgl2_only, min_version_to_compare)
         else:
           test = os.path.join(current_dir, test_name)
           if webgl_version > 1:
             test += '?webglVersion=' + str(webgl_version)
           test_paths.append(test)
 
     return test_paths