Add option to disable RSS graph or scale memory chart axis

Hi -

When profiling a desktop application, often the Resident Set Size is so large that autoscaling causes the memory timeline chart to be of limited use.

It would be useful to be able to hide the RSS graph, or scale the axis so that the other graphs can be seen.

Many thanks.

首先定位 DevTools 内存时间线图表及其 RSS 系列。确定预期行为是隐藏 RSS、改变坐标轴缩放，还是同时支持这两种选项；该 issue 未指定文件或测试。当 RSS 较大时其他内存图仍然有用，并且所选行为由适当的测试覆盖时，即视为完成。

由索引模型根据 Issue 内容生成。