Avoid duplicate route id in Gpu Process.

GpuChannelManager generates unique routeid for every new
imagetransportsurface. On our side, we register a routeid
for our display channel. Depending on our routeid, we will
conflict with the one generated by GpuChannelManager. To avoid
this, now we hardcore our routeid with a negative sign to be
unique from the ones generated by GpuChannelManager. This is
one of the main reason for random crashes. This also fixes
the crash in multi window case.
Gardening: Update to latest Chromium revision.

Effecting CL: https://codereview.chromium.org/49303007
OzoneDisplay: Remove unused private member
Missing break statement
patches: Fix script accordingly new pin practices

origin/master now contains the newest fetched tip of Chromium tree and it's not
actually the version Ozone-Wayland wants to be build with. Instead the script
needs to create a new hacking branch based on 'master', assuming 'master' is
the branch used when last synced (gclient sync).