Delete some dead reflection code in CompositedLayerMapping.

BUG=

Review URL: https://codereview.chromium.org/301773002

git-svn-id: svn://svn.chromium.org/blink/trunk@174921 bbb929c8-8fbe-4397-9dbb-9b2b20218538
TestResultServer: Add failure 'LEAK'

BUG=377330
TEST=test-webkitpy, jsonresults_unittest.py
NOTRY=true

Review URL: https://codereview.chromium.org/296423002

git-svn-id: svn://svn.chromium.org/blink/trunk@174922 bbb929c8-8fbe-4397-9dbb-9b2b20218538