How to install webkitgtk1 on RHEL7
You can download webkitgtk-2.2.4-1.el7.x86_64.rpm for rhel7 for example from http://rpm.pbone.net/index.php3/stat/4/idpl/27127038/dir/redhat_el_7/com/webkitgtk-2.2.4-1.el7.x86_64.rpm.html and then install by rpm -ihv webkitgtk-2.2.4-1.el7.x86_64.rpm
It need libsecret,libwebp, gstreamer1-plugins-base packages - yuu can install it from rhel7/centos7
Alternativly, but "right way" - yuu can add whole epel repository:
yum install epel-release
And then install webkitgtk package by
yum install webkitgtk