Backout changesets 37f9a5424227, c1578a4fc86d and a417424f9213 (for bugs 933354, 929021 and 923193 respectively) while we figure out performance regressions

--HG--
extra : rebase_source : e4a004a15c92b5a8a8b780e7da779ac86d1c29be
Bug 936628: Add media query to check for whether we have a color picker backend available. r=jimm
Bug 907463. Ignore result of very big canvas reftest. r=roc DONTBUILD
Bug 928050 - Specify whether to iterate over atoms zone (r=bhackett)
Bug 853423 - Block speculative connections for local IP addresses r=mcmanus
Bug 853423 - Tests to verify speculative connection are blocked for local IP addresses r=mcmanus
Backout changesets 238b3c81f42c and rest of a417424f9213 (bug 928798 and rest of bug 923193 respectively)

--HG--
extra : rebase_source : a453412840da1eacb9d5c6f9f553137efa050e0c
Bug 818287 Remove data URL prefix from screenshots. r=dhunt
Merge mozilla-central and inbound
Bug 894914 - Disable test_postMessage_closed.html on Android & B2G due to intermittent failures.
Bug 915350 - Disable testBookmark due to intermittent failures.
Bug 936927 - Build the HTML parser in unified mode; r=hsivonen
Bug 906964 - ARM: leave some head-room in the double pools to help avoid bailing out which causes compilation failure for asm.js code. r=mjrosenb
Bug 936341 - Get NSPR emulation working on BSD. r=billm
Bug 936226 - Disable frequent robocop failures on Android x86; r=dminor
Bug 935453 - Gather telemetry about dangerous encodings and encodings we might remove. r=emk,sstamm.
Bug 930771 - Ensure that overlay scrollbars don't leave behind white bands after fading out. r=jimm
Bug 913254 - Disable testReaderMode due to intermittent failures.
No bug - Alphabetize robocop.ini. DONTBUILD
Bug 933952 - The NO_DELTA flag in CharacterInfo is unnecessary; r=evilpies