Bug 940842 - 1/3 - Add will-change CSS property - r=dbaron

The current spec draft is at:
http://tabatkins.github.io/specs/css-will-change/

This CSS property is disabled by default and can be enabled by toggling:
  layout.css.will-change.enabled
Bug 940842 - 2/3 - Implement will-change in layers-building code - r=mattwoodrow
Bug 940842 - 3/3 - Add a mochitest covering repaint heuristics with will-change - r=mattwoodrow
Bug 965082 - Unify duplicate bits of state of proxies. r=mrbkap,r=gabor

Conceptually, these all boil down to "is this a security wrapper?"
Bug 965082 - Only run the {get,set}PrototypeOf override for non-SecurityWrappers. r=mrbkap,r=gabor
Bug 965082 - Tests. r=mrbkap,r=gabor
Bug 963738 - Fix some false positives in the Array analysis; r=jonco
Bug 875013 - VPATH removals in build, roboextender, crashreporter; r=ted
Bug 951293 - Fix speculative connection limiting. r=mcmanus
Bug 959333 - HTTP/2 should say so in the status line. r=mcmanus
Bug 918289 - Remove video sources from MediaElements in TextTrack tests where they are not needed. r=cpearce
Bug 956857 - Fix busted semantics for subject parameter in  "xpcom-category-entry-removed" notification. r=bsmedberg
Bug 958348 - Allow swapping the current and previous exception filters. r=dmajor
Bug 959257 - Google's search box may not emit caret move events. r=tbsaunde
Bug 961919 - Re-enable all of the subtests in test_reftests_with_caret.html. r=roc
Bug 963030 - AArch64 support for IPC. r=bsmedberg
Bug 964507: Add mochitests for Debugger.Source.protoype.element and .elementAttributeName. r=bz
Bug 942359 - More Promises tests on workers. r=baku

--HG--
extra : rebase_source : 202611f82f7fc1272229f847bee09e6fb39a336b
Bug 965030 - Pass the correct positioned frame to PushAbsoluteContainingBlock. r=roc
Bug 946952 - Run a 'compressed' paint up to 1 second after skipping the ColorLayer optimization. r=roc