ZHANGJIAKOU, China—There were doubts, and falls, and fear for Chloe Kim. Ultimately, there was a gold medal, too. The 21-year-old American’s second straight trip to the top of the Olympic podium—a trip taken Thursday after a terrible pre-contest training session that made her wonder if she really could make it—came with a timely reminder not only for her, but for everyone else paying attention to her latest domination of the halfpipe. “It’s unfair to be expected to be perfect, and I’m not perfect in every way,” Kim said. Kim has come as close as anyone this side of Shaun White to “perfect” on a halfpipe. Because of that, there was no real drama coming in about who would win the women’s contest at the Secret Garden Olympic halfpipe. Kim put her stamp on this one early, knocking down a perfect run on her first trip down the halfpipe. She accomplished …