Fix path for CharacterPropertyDataGenerator.h (platform/fonts -> platform/text)

Looks like the header has moved but the #if defined(USING_SYSTEM_ICU)
branch was not updated.

BUG=584920

Review URL: https://codereview.chromium.org/1893293002

Cr-Commit-Position: refs/heads/master@{#388178}
1 file changed