Implement direction-specific touch-action values.
Now that change https://codereview.chromium.org/
1137483003/ has landed
fix up change (https://codereview.chromium.org/
1131093002/) by removing
the #if 0 and static casts.
This change doesn't provide an implementation of touch-action
because it has previously landed. But it activates
the code paths because now pan-left/pan-right/pan-up/pan-down
are passed transformed correctly between the blink and content
APIs.
BUG=476556
TEST=content_unittests
Review URL: https://codereview.chromium.org/
1137153003
Cr-Commit-Position: refs/heads/master@{#330525}