Unmark ContextLost_WebGLBlockedAfterJSNavigation as flaky.

The underlying failure has been fixed.

Tbr: danakj@chromium.org
Bug: 882103
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: I195c7a76e020542667d92a642e4631d78bf1c7a3
Reviewed-on: https://chromium-review.googlesource.com/1226460Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591258}

content/test/gpu/gpu_tests/context_lost_expectations.py

@@ -55,8 +55,6 @@ class ContextLostExpectations(GpuTestExpectations):
               ['android'], bug=609629)
 
     # Flaking on Nexus 5X
-    self.Flaky('ContextLost_WebGLBlockedAfterJSNavigation',
-               ['android'], bug=882103)
     self.Flaky('ContextLost_WebGLUnblockedAfterUserInitiatedReload',
               ['android'], bug=879423)
     self.Fail('ContextLost_WorkerRAFAfterGPUCrash',