/**
 * Measures how long the gpu spent on a frame, using timestamp queries written
 * around the render pass.
 *
 * Waiting on `onSubmittedWorkDone` would give the same answer and stop the cpu
 * from running ahead, which is the thing worth measuring in the first place.
 * These are read back a frame or more later instead, and a frame is skipped
 * while a previous read is still mapping, so the sample rate drops rather than
 * the frame rate.
 */
export declare class GpuTimer {
    private readonly querySet;
    private readonly resolveBuffer;
    private readonly readBuffer;
    private reading;
    /** Gpu time for the most recently measured frame, in milliseconds. */
    lastMs: number;
    private constructor();
    /** Null where the adapter does not offer timestamps, which is common. */
    static create(device: GPUDevice): GpuTimer | null;
    /** Passed to beginRenderPass so the gpu stamps the pass boundaries. */
    timestampWrites(): GPURenderPassTimestampWrites;
    /** Copies the stamps out, inside the frame's own encoder. */
    resolve(encoder: GPUCommandEncoder): void;
    /** Reads the previous frame's stamps without blocking this one. */
    sample(): void;
    destroy(): void;
}