Disable blitframebuffer-size-overflow on Linux NVIDIA P400

This seems to cause a lost device, which causes the next test to fail.

BUG=709320
TBR=kbr@chromium.org
NOTRY=true
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2804963003
Cr-Commit-Position: refs/heads/master@{#462830}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -712,6 +712,9 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
     # Linux NVIDIA Quadro P400
     self.Fail('deqp/functional/gles3/multisample.html',
         ['linux', ('nvidia', 0x1cb3)], bug=702861)
+    # This test causes a lost device and then the next test fails.
+    self.Skip('conformance2/rendering/blitframebuffer-size-overflow.html',
+        ['linux', ('nvidia', 0x1cb3)], bug=709320)
 
     # Linux Intel
     self.Fail('conformance2/extensions/ext-color-buffer-float.html',