Release gpu::ContextGroup in gpu::InProcessCommandBuffer on GPU thread

gpu/ipc/in_process_command_buffer.cc

Index: gpu/ipc/in_process_command_buffer.cc
diff --git a/gpu/ipc/in_process_command_buffer.cc b/gpu/ipc/in_process_command_buffer.cc
index fd1e6b2a30fd7d183562ec2a574bda79be3aa081..222edd5d802272a53e04308b67121e7305a163f7 100644
--- a/gpu/ipc/in_process_command_buffer.cc
+++ b/gpu/ipc/in_process_command_buffer.cc
@@ -465,6 +465,7 @@ bool InProcessCommandBuffer::DestroyOnGpuThread() {
     sync_point_order_data_ = nullptr;
   }
   gl_share_group_ = nullptr;
+  context_group_ = nullptr;
 
   base::AutoLock lock(task_queue_lock_);
   std::queue<std::unique_ptr<GpuTask>> empty;