V8: Fix coverage data upload.
V8: Fix coverage data upload.

BUG=chromium:568949
TBR=kjellander@chromium.org, tandrii@chromium.org

Review URL: https://codereview.chromium.org/1797393006

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@299342 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build