Move files in wtf/ to platform/wtf/ (Part 10).

This patch moves all the remaining files in wtf/text/:

    In text/:
        Base64.{h,cpp}, Collator.h, icu/CollatorICU.cpp,
        ParsingUtilities.h, StringUTF8Adaptor.h,
        TextCodecASCIIFastPath.h, TextCodec.{h,cpp}, TextCodecICU.{h,cpp},
        TextCodecLatin1.{h,cpp}, TextCodecReplacement.{h,cpp},
        TextCodecUserDefined.{h,cpp}, TextCodecUTF{8,16}.{h,cpp},
        TextEncoding.{h,cpp}, TextEncodingRegistry.{h,cpp},
        TextPosition.{h,cpp}

Also, wtf/text/OWNERS is moved to platform/wtf/text/ at this time.

BUG=691465

Review-Url: https://codereview.chromium.org/2764283002
Cr-Commit-Position: refs/heads/master@{#459033}
45 files changed