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-Commit-Position: refs/heads/master@{#471654}
2 files changed