b=932400 change stream ordering to get feedback DelayNode output before supplying input r=roc

Previously downstream nodes from DelayNodes in cycles sometimes received stale
output from the previous MSG iteration.

Also, if two cycles share a common path, they will now *both* be treated as
cycles, either by muting or by enforcing minimum delay.  Previously, marking
one cycle first could prevent detection of other cycles in the same SCC.

--HG--
extra : rebase_source : 82892c538c5ce514165b5f975474df15b99e3d2b
Bug 1022434 - Extract crypto information from MP4 demuxer; r=cpearce
* * *
Bug 1022434 - "[EME] Expose decryption data in MP4Samples" []
Bug 950745 - Flag when we're processing urgent messages and disallow certain activities (r=bsmedberg,luke)
Bug 1038844 - Implement a COW opt-out for automation. r=gabor,sr=mrbkap
Bug 1038844 - Flip the scary automation pref for crashtests and marionette. r=jgriffin
Bug 1038844 - Use the opt-out for the SpecialPowers scope. r=mrbkap,r=ted
Bug 1025768 - Restore eager SourceBuffer switching.  r=cajbir
Bug 1039917 - Fix clang and gcc warnings in webrtc/signaling. r=jesup
bug 991153 follow up: fix a couple of incorrectly signed vars. (r=dholbert)
Bug 1039207: Don't hardcode double-sized registers when popping with a mask. (r=dougc)
Bug 991153 fallout: Flip a bit in the simulator's constructor (r=dougc)
Bug 1023677 - Mark BasicCompositor as not supporting component alpha layers. r=roc
Bug 1023677 - Don't repeat layer building if there was only a single layer. r=roc
Bug 1023677 - Don't set mSupportComponentAlphaChildren unless we actually have them. r=roc
Bug 1023677 - Don't flatten active transform layers. r=roc
Bug 1039145 - Part 1: Clean up AreComponentAlphaLayersEnabled. r=roc
Bug 1039145 - Part 2: Fully remove component alpha/background copying support from BasicCompositor. r=roc
Bug 1037028 - More namespace cleanups in imglib, r=seth
Backed out changeset 49c713f92304 (bug 1039145)
Backed out changeset b049e0ae4d1d (bug 1039145)