Adding CHECK macro to debug crash.

Moving a DCHCEK to CHECK and adding a new CHECK macro to debug crash
which are hard to reproduce on local devices. This CHECK will soon
be moved back to DCHECK.

Bug: 892354
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: I44e237db73cec5259b90bb312e7940b41553d332
Reviewed-on: https://chromium-review.googlesource.com/c/1282104Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: vikas soni <vikassoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599885}

ui/gl/gpu_timing.cc

@@ -524,7 +524,8 @@ void GPUTimer::Reset() {
 }
 
 void GPUTimer::QueryTimeStamp() {
-  DCHECK(gpu_timing_client_->gpu_timing_);
+  CHECK(gpu_timing_client_);
+  CHECK(gpu_timing_client_->gpu_timing_);
   Reset();
   time_stamp_result_ = gpu_timing_client_->gpu_timing_->DoTimeStampQuery();
   timer_state_ = kTimerState_WaitingForResult;