Fixed a bug that was introduced when we started deprecating 32bit libraries on 64bit systems.

This needs a little bit of explanation. Normally, we would want to restructure
the code to have separate variables for "--lib32" and for the result of the
"yes_no" question. But that requires more global changes.

Instead, in this case, we want to very clearly document that we added an
early "if" statement to break out. And this is intended to be a temporary
measure until the entire feature is fully removed.

So, I instead opted for resetting the "do_inst_lib32" variable -- and a lengthy
comment explaining this decision.

BUG=233047
TEST=run with --lib32 and verify that entering "N" aborts the installation.

Review URL: https://chromiumcodereview.appspot.com/14166013

git-svn-id: http://src.chromium.org/svn/trunk/src/build@195950 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

install-build-deps.sh

@@ -297,6 +297,21 @@ if [ "$(uname -m)" = "x86_64" ]; then
     echo
     echo "Installation complete."
     exit 0
+  else
+    # This conditional statement has been added to deprecate and eventually
+    # remove support for 32bit libraries on 64bit systems. But for the time
+    # being, we still have to support a few legacy systems (e.g. bots), where
+    # this feature is needed.
+    # We only even give the user the option to install these libraries, if
+    # they explicitly requested doing so by setting the --lib32 command line
+    # flag.
+    # And even then, we interactively ask them one more time whether they are
+    # absolutely sure.
+    # In order for that to work, we must reset the ${do_inst_lib32} variable.
+    # There are other ways to achieve the same goal. But resetting the
+    # variable is the best way to document the intended behavior -- and to
+    # allow us to gradually deprecate and then remove the obsolete code.
+    do_inst_lib32=
   fi
 
   echo "WARNING"