Replace "field_type_path" with "include_paths" in CSSProperties.json5.

In CSSProperties.json5, to deal with type_names that are defined in
other files, we use the "field_type_path" parameter. For example, if we
wanted to use "Length" as the type_name, we can specify
"field_type_path" as "platform/Length" and the generator will
automatically include "platform/Length.h". We would also deduce that
the type_name is Length. However, this does not cater for type_names
like "Vector<String>", where multiple files need to be included.

This patch generalises "field_type_path" to "include_paths", which is
simply a list of files containing definitions for the types in
type_name. Since "include_paths" can contain multiple files, we can no
longer deduce the type_name, so we have to explicitly specify the
type_name.

BUG=628043

Review-Url: https://codereview.chromium.org/2904483003
Cr-Commit-Position: refs/heads/master@{#474928}
4 files changed