Compile fix for Android 32-bit.

R=tsepez@chromium.org
TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/25903002

git-svn-id: svn://svn.chromium.org/blink/trunk@158825 bbb929c8-8fbe-4397-9dbb-9b2b20218538