Boot to Ubuntu live, install hfsprogs/hfsutils and mount the OSX partition. Now connect an external USB HDD and backup any data you need to the external device.
Somehow the gptsync command, from what i can see on the screenshot, converted the partition table to mbr.
After you have backed up the data, format the whole HDD, and start over. No need to use Gparted to mark a partition active (On GPT).
If your system does not support UEFI and you insist on Chameleon, format the HDD to MBR, else perhaps look into Clover and format the HDD to GPT. Both bootloaders can be booted from an USB stick without alternations to your system.
I remember having this issue with the Intel HD4000 graphics in 10.10/10.11 due to patched kexts. The only way to prevent this issue was not to patch the kexts and move on with bad graphics, i decided to wait the 60 sec on every boot.
The kexts and patched which causes the issue are in the Dell 7720 topic in my sig.