Replace further questionable HashMap::add usages in bindings

BUG=390928
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/411273002

git-svn-id: svn://svn.chromium.org/blink/trunk@178823 bbb929c8-8fbe-4397-9dbb-9b2b20218538
    void doWriteUint32(uint32_t value)
    {
        doWriteUintHelper(value);
    }

    void doWriteUint32(uint32_t value)
    {
        doWriteUintHelper(value);
    }
