Track event handlers on windows

This patch makes EventHandlerRegistry keep track of event handlers
registered on the window object.

TEST=fast/events/scroll-event-handler-count.html,fast/events/scroll-event-handler-reused-window.html
BUG=359566

Review URL: https://codereview.chromium.org/240343002

git-svn-id: svn://svn.chromium.org/blink/trunk@173552 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Refactor deprecated Skia calls.

Use equivalent non-deprecated methods instead.

R=reed@google.com,senorblanco@chromium.org,abarth@chromium.org

Review URL: https://codereview.chromium.org/269283008

git-svn-id: svn://svn.chromium.org/blink/trunk@173553 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add console warning for canceling uncancelable TouchEvent

BUG=370149

Review URL: https://codereview.chromium.org/273503004

git-svn-id: svn://svn.chromium.org/blink/trunk@173554 bbb929c8-8fbe-4397-9dbb-9b2b20218538