content: Delete webkit_support.h
content: Delete webkit_support.h

This file was just a placeholder, including blink_test_environment.h
waiting for Blink to be updated.

Now that Blink was updated and rolled into Chromium, we can remove it.

Chromium side (part 1) ->
https://src.chromium.org/viewvc/chrome?revision=288636&view=revision
Blink side (part 2) ->
https://src.chromium.org/viewvc/blink?revision=179977&view=revision
Chromium side (part 3) -> this patch

BUG=None
TEST=webkit_unit_tests
R=avi@chromium.org

Review URL: https://codereview.chromium.org/463603003

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@289200 0039d316-1c4b-4281-b951-d872f2087c98

bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,littlstar/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,littlstar/chromium.src