Tell SVN to ignore the LayoutTests/w3c directory via svn:ignore.

(Change not uploaded to Rietveld as gcl can't deal w/ property-only changes).

TBR=thakis
BUG=330371




git-svn-id: svn://svn.chromium.org/blink/trunk@164634 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use StringBuilder::appendLiteral() when possible in MarkupAccumulator

Use StringBuilder::appendLiteral() when possible in MarkupAccumulator instead
of StringBuilder::append() as it is a bit more efficient.

R=adamk, abarth

Review URL: https://codereview.chromium.org/114103005

git-svn-id: svn://svn.chromium.org/blink/trunk@164635 bbb929c8-8fbe-4397-9dbb-9b2b20218538