Bug 864948 - Disable pgo and don't link to dynamic win runtime and glue libs when building metrotestharness. r=glandium
Bug 856374 - Check if output string is empty when serializing. r=smaug.
Bug 861887 Review comments for prev patch r=bholley

--HG--
extra : rebase_source : 7f91680f5f7249c9fb09708eb790bdc19c779c67
Bug 864164 - Part 2: Send the AudioBufferSourceNode buffer parameter changes to the stream; r=padenot
Bug 864164 followup - Also send the params to the stream when setting the buffer. r=ehsan
Bug 856079 - Merge ShadowLayer and LayerComposite (keeping the later). r=nrc
Bug 864788 - Add fuzzing to test 784573-1.html. DONTBUILD r=ajones