Revert "Reenable GPUProcessCrashesExactlyOncePerVisitToAboutGpuCrash"

This reverts commit 8bd7e583.

Reason for revert: Still flaky :( https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac_chromium_rel_ng/166516

Original change's description:
> 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/1285526
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Commit-Queue: enne <enne@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#600813}

TBR=kbr@chromium.org,enne@chromium.org

Change-Id: I0dd172bd7db86982f9b1bf49e2a57c059958d348
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
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
Reviewed-on: https://chromium-review.googlesource.com/c/1290950Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601098}

content/test/gpu/gpu_tests/context_lost_expectations.py

@@ -68,3 +68,7 @@ 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)