Add a macro to ignore the return value of a function.
Add a macro to ignore the return value of a function.

The more typical (void)(function()) does not work with GCC when explicitly marking the -Wunused-value attribute on a function.

I plan to land the fix for bug 42904 in stages:

1) add this macro
2) fix some instance (either a misuse of release(), or just add this macro to it)
3) fix some instance (either a misuse of release(), or just add this macro to it)
....
n - 1) fix some instance (either a misuse of release(), or just add this macro to it)
n) enable the WARN_UNUSED_VALUE attribute on {scoped_ptr,scoped_ptr_malloc,scoped_array}.release()

BUG=42904
TEST=none

Review URL: http://codereview.chromium.org/1794012

git-svn-id: http://src.chromium.org/svn/trunk/src@46252 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 95fdb198da37b58bc403e3f10210cfe4cc3fdf8b
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser