Add mojo bindings backpointer tests.

Add mojo bindings backpointer tests.

Simple bit-flipping won't generate negative offsets (e.g. large
positive offsets that overflow), so we add a test where we specifically
create the possibility of such.

Also simplify argument passing in the cpp -> js direction, since there isn't
a need to build lists here.  We're only interested in the other direction.

Remove some stray "explicit" keywords and reduce the echo
test iterations since it doesn't prove much.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271806

[viettrungluu, 2014-05-20 18:10:23]

lgtm w/nit

https://codereview.chromium.org/292243002/diff/40001/mojo/apps/js/test/js_to_...
File mojo/apps/js/test/js_to_cpp_unittest.cc (right):

https://codereview.chromium.org/292243002/diff/40001/mojo/apps/js/test/js_to_...
mojo/apps/js/test/js_to_cpp_unittest.cc:315: explicit
BackPointerCppSideConnection() : termination_seen_(false) {}
nit: no need for "explicit"

[Tom Sepez, 2014-05-20 18:11:24]

Trung, please review.  Thanks.

[Tom Sepez, 2014-05-20 18:18:09]

The CQ bit was checked by tsepez@chromium.org

[commit-bot: I haz the power, 2014-05-20 18:18:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tsepez@chromium.org/292243002/60001

[commit-bot: I haz the power, 2014-05-21 01:59:13]

Change committed as 271806