Reland of gpu: GPU service scheduler.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 5f75f599fed356ce9ac1aa264ebdc8cf8d07b3a4..3651a90c5494e794652439e1b2b18b4e8a79b058 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -16030,6 +16030,9 @@ error::Error GLES2DecoderImpl::HandleInsertFenceSyncCHROMIUM(
   const uint64_t release_count = c.release_count();
   if (!fence_sync_release_callback_.is_null())
     fence_sync_release_callback_.Run(release_count);
+  // Exit inner command processing loop so that we check the scheduling state
+  // and yield if necessary as we may have unblocked a higher priority context.
+  ExitCommandProcessingEarly();
   return error::kNoError;
 }