Handle word-spacing for leading white space on SVG text

SVGTextLayoutEngineSpacing checking if the current and last characters
were non-nuls before attempting to apply word-spacing. This would mean
that we'd never add word-spacing at the beginning of a text box.
Remove the checks for non-nuls.

Bug: 902839
Change-Id: I751e1bd1317f7411960d137b7e55a3b83e8cb0df
Reviewed-on: https://chromium-review.googlesource.com/c/1326156
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#606528}
3 files changed