Move CursorList to its own file.

When we generate external types like Length in ComputedStyle, we specify
the path to the type (e.g. "platform/Length"). We then deduce the name
of the type from the path ("Length"). This means that the type must be
stored in a file with the same name.

This patch moves CursorList to its own file so that it can be generated.

BUG=628043

Review-Url: https://codereview.chromium.org/2880963002
Cr-Original-Commit-Position: refs/heads/master@{#471654}
Committed: https://chromium.googlesource.com/chromium/src/+/79e3cc6d695903af9f32b770fd80f67e878587e7
Review-Url: https://codereview.chromium.org/2880963002
Cr-Commit-Position: refs/heads/master@{#471682}
3 files changed