Add eventSender support for web pointer properties in touch points.

This support is needed for web pointer property propagation layout tests.

This CL is a part of a patch series:
 1.  https://codereview.chromium.org/1253183005/
     for new WebPointerProperties fields
 2.  https://codereview.chromium.org/1260693003/ (this)
 3a. https://codereview.chromium.org/1192563002/
     for handling tilt in Blink event handlers
 3b. https://codereview.chromium.org/1192463008/
     for handling pointer type in Blink event handlers
 4a. https://codereview.chromium.org/1187273004/
     for handling tilt in Chromium event handlers
 4b. https://codereview.chromium.org/1190013002/
     for handling pointer type in Chromium event handlers

BUG=514360

Review URL: https://codereview.chromium.org/1260693003

Cr-Commit-Position: refs/heads/master@{#341299}
2 files changed