public void onFailure() {
    Preconditions.checkState(mState == ImageRequestState.STARTED);
    mState = ImageRequestState.FAILURE;
    mFinishTime = System.currentTimeMillis();
    final long elapsedTime = mFinishTime - mStartTime;
    mPerfListener.reportFailure(elapsedTime);
    FLog.i(TAG, "Image [%s]: failed after %d ms", mTag, elapsedTime);
  }
Tracks state of image request.

<p>Components that implement {@link Instrumented} interface can use this class to track their
requests.
samples/scrollperf/src/main/java/com/facebook/samples/scrollperf/instrumentation/Instrumentation.java