Mark a newly added test as fail on Nexus 6

content/test/gpu/gpu_tests/webgl_conformance_expectations.py

Index: content/test/gpu/gpu_tests/webgl_conformance_expectations.py
diff --git a/content/test/gpu/gpu_tests/webgl_conformance_expectations.py b/content/test/gpu/gpu_tests/webgl_conformance_expectations.py
index 488a7c2e41379d0e94f4d2908d97d52b54670141..f484f5f9267ec711d6ccad0361e6b246efb00680 100644
--- a/content/test/gpu/gpu_tests/webgl_conformance_expectations.py
+++ b/content/test/gpu/gpu_tests/webgl_conformance_expectations.py
@@ -581,6 +581,9 @@ class WebGLConformanceExpectations(GpuTestExpectations):
         ['android', ('qualcomm', 'Adreno (TM) 420')], bug=499555)
     self.Fail('conformance/uniforms/uniform-samplers-test.html',
         ['android', ('qualcomm', 'Adreno (TM) 430')], bug=663071)
+    self.Fail('conformance/offscreencanvas/' +
+        'context-attribute-preserve-drawing-buffer.html',
+        ['android', ('qualcomm', 'Adreno (TM) 420')], bug=693135)
     self.Fail('WebglExtension_EXT_sRGB',
         ['android',
          ('qualcomm', 'Adreno (TM) 420'), ('qualcomm', 'Adreno (TM) 430')])