Move core/platform/text/Locale* to platform/text

I pulled on a few strands, and I ended up moving the Locale code into
blink_platform.dll.

TBR=eseidel@chromium.org
BUG=297477

Review URL: https://codereview.chromium.org/26113002

git-svn-id: svn://svn.chromium.org/blink/trunk@158983 bbb929c8-8fbe-4397-9dbb-9b2b20218538