DecodeEscapeSequences shouldn't use bloatedCharacters()

We're sweeping the codebase to remove callers of bloatedCharacters so we can
remove the mechanism entirely. This code doesn't need to use bloatedCharacters.

R=tsepez@chromium.org
BUG=254708

Review URL: https://chromiumcodereview.appspot.com/18328025

git-svn-id: svn://svn.chromium.org/blink/trunk@153659 bbb929c8-8fbe-4397-9dbb-9b2b20218538
LocaleICU shouldn't use bloatedCharacters()

This CL is another choice between storing 16 bit characters in the binary and
having a memcpy. As before, I've left the 8 bit characters in the binary and
kept the memcpy. I think that's the right trade-off here. (Note: We had the
same memcpy prior to this Cl.)

This CL also gave me the chance to introduce String::appendTo, which I'm
planning to use in a few more places.

R=eseidel
BUG=254708

Review URL: https://chromiumcodereview.appspot.com/18519009

git-svn-id: svn://svn.chromium.org/blink/trunk@153660 bbb929c8-8fbe-4397-9dbb-9b2b20218538
parseQualifiedName shouldn't use bloatedCharacters()

R=pdr
BUG=254708

Review URL: https://chromiumcodereview.appspot.com/18533005

git-svn-id: svn://svn.chromium.org/blink/trunk@153661 bbb929c8-8fbe-4397-9dbb-9b2b20218538