Reenable GPUProcessCrashesExactlyOncePerVisitToAboutGpuCrash

This was flaky, but should be fixed.

Bug: 878258
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I3e037e41339ddff9d46ec0a7ca7679064a3322e0
Reviewed-on: https://chromium-review.googlesource.com/c/1285526Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: enne <enne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600813}

content/test/gpu/gpu_tests/context_lost_expectations.py

@@ -68,7 +68,3 @@ class ContextLostExpectations(GpuTestExpectations):
               ['android', ('qualcomm', 'Adreno (TM) 420')], bug=611906)
     self.Fail('ContextLost_WebGLContextLostFromQuantity',
               ['android', ('qualcomm', 'Adreno (TM) 420')], bug=611906)
-
-    # Temporary until Ganesh fix is made. Too flaky to mark as flaky.
-    self.Fail('GpuCrash_GPUProcessCrashesExactlyOncePerVisitToAboutGpuCrash',
-               ['win'], bug=878258)