Remove stale Skia suppressions

These were addressed in:
https://skia.googlesource.com/skia.git/+/8b50ac242bc3a41cf81d5d9bbc24d49b9f85d834
https://skia.googlesource.com/skia.git/+/a5cf665997d73169e2f5260eaf9643af1f309762

Remove the corresponding suppressions.

Bug: skia:3294, 258499
Change-Id: Ib1fa1e4769dc76b81eac6ffd7389f9f6a6504ce0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1643028
Commit-Queue: Mike Klein <mtklein@chromium.org>
Auto-Submit: David Benjamin <davidben@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#665912}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: b20cc846541fa5a6a364ae9af91d28cae8f38fc3

sanitizers/tsan_suppressions.cc

@@ -87,9 +87,6 @@ char kTSanDefaultSuppressions[] =
     "race:SamplingStateScope\n"
     "race:g_trace_state\n"
 
-    // http://crbug.com/258499
-    "race:third_party/skia/include/core/SkRefCnt.h\n"
-
     // http://crbug.com/268924
     "race:base::g_power_monitor\n"
     "race:base::PowerMonitor::PowerMonitor\n"
@@ -148,9 +145,6 @@ char kTSanDefaultSuppressions[] =
     // http://crbug.com/490856
     "deadlock:content::TracingControllerImpl::SetEnabledOnFileThread\n"
 
-    // https://code.google.com/p/skia/issues/detail?id=3294
-    "race:SkBaseMutex::acquire\n"
-
     // Lock inversion in third party code, won't fix.
     // https://crbug.com/455638
     "deadlock:dbus::Bus::ShutdownAndBlock\n"