Fix the remaining warnings (on android 32 bit debug) and enable -Wall -Werror for android.

BUG=312287
R=peter@chromium.org, thakis@chromium.org
TBR=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/59773004

Patch from Lazlo Gombos <l.gombos@samsung.com>.

git-svn-id: svn://svn.chromium.org/blink/trunk@161356 bbb929c8-8fbe-4397-9dbb-9b2b20218538