Cleanup change to the createImageCHROMIUM api to follow up https://codereview.chromium.org/255713008/

BUG=

Review URL: https://codereview.chromium.org/267283003

git-svn-id: svn://svn.chromium.org/blink/trunk@173560 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Auto-rebaseline for r173545

http://src.chromium.org/viewvc/blink?view=revision&revision=173545

BUG=367088
TBR=dominik.rottsches@intel.com

Review URL: https://codereview.chromium.org/270403003

git-svn-id: svn://svn.chromium.org/blink/trunk@173561 bbb929c8-8fbe-4397-9dbb-9b2b20218538