Shape Detection: add OWNERS to services/shape_detection/

 cp third_party/WebKit/Source/modules/shapedetection/OWNERS services/shape_detection/

BUG=659138
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.mac:mac_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2801893006
Cr-Commit-Position: refs/heads/master@{#462999}

services/shape_detection/OWNERS

+mcasas@chromium.org
+reillyg@chromium.org
+
+# COMPONENT: Blink>ImageCapture
+# TEAM: device-dev@chromium.org