Update git hashes of Blink commits

[beverloo]

Now that the Chromium and Blink repositories merged, all Blink commits are linking to an unused repository. While @primiano tells me that it'll stick around, I'd rather remove the repository from the code entirely and link to the new SHAs.

Example: https://chromium.googlesource.com/chromium/blink/+/134c13894bf5fb087f9017698547ec12c963bfa6

Should instead link to: https://chromium.googlesource.com/chromium/src/+/87ca9556952b5570a2f1c0cb8035bb87602f790b