Nuke Telemetry::* from orbit

[classilla]

Using dummy preprocessor macros in toolkit/components/telemetry for things like Telemetry::Accumulate, we should be able to eliminate much dead code.

It's the only way to be sure.

[classilla]

First cut at this reduced XUL down only by about 300K. Substantial changes were needed for anything that calls Services.telemetry and I still have to look at JS in devtools/.

Since tele isn't being called in hot loops there is probably a small win here but it feels like only an incremental one and the changes required are massive. I'd rather introduce the whole thing for an FPR release. For 45.6 let's just yank it from the UI facing sections:

• kill tele in nsBrowserGlue.js (especially _handleURLBarTelemetry but there are others)
• kill in tabbrowser.xml
• kill in browser.js (especially OpenBrowserWindow)

[classilla]

hg revert --no-backup browser/components/nsBrowserGlue.js browser/base/content/tabbrowser.xml browser/base/content/browser.js

[classilla]

This doesn't include devtools.
no_tele.diff.txt

[classilla]

Did the 45.6 parts. Looking at GC/CC for 45.7 or .8.