Enable GetDisplayMedia by default in blink

See https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/eKS6bOz9a_o
for Intent to Ship and lgtms.

Bug: 326740
Change-Id: I2d8cec26bae32281e50137dfd1616926b66e61a8
Reviewed-on: https://chromium-review.googlesource.com/c/1292439
Commit-Queue: Emircan Uysaler <emircan@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607287}
3 files changed