Bug 984711 part 7: Add back mochitest for min-[size]:auto. (no review; just an unbitrotted backout)

This reverts changeset edd98255e81d from bug 848539.
Bug 984711 part 8: Remove pref-setting mochitest wrapper for min-[size]:auto mochitest. (no review; tweaking existing test)
Bug 984711 part 9: Rename file_flexbox_min_size_auto.html to test_flexbox_min_size_auto.html, now that its obsolete wrapper is gone. (no review)

--HG--
rename : layout/style/test/file_flexbox_min_size_auto.html => layout/style/test/test_flexbox_min_size_auto.html
Bug 1037177 part 1: Make FlexItem() constructor take a reflow state as a parameter, to reduce arg-count and get faster access to style structs. r=mats
Bug 1037177 part 2: Rename ResolveFlexItemMaxContentSizing to ResolveAutoFlexBasisAndMinSize. r=mats
Bug 1037177 part 3: Split out flexbox's auto-height-measuring code into its own dedicated function. r=mats
Bug 1037177 part 4: Call ResolveAutoFlexBasisAndMinSize at the end of GenerateFlexItemForChild, instead of just after it. r=mats
Bug 1037177 part 5: Update documentation for GenerateFlexItemForChild & helpers. (comment-only, no review)
Bug 1015474 part 1: Update behavior of "min-width:auto"/"min-height:auto" to match current spec text. r=mats

This updates min-width:auto / min-height:auto to now take several more things
into account, beyond just a flex item's min-content size. Now we'll also
consider its used 'flex-basis', its main max-size property ('max-width' or
'max-height'), and its intrinsic ratio & any constraints in the other
dimension.
Bug 1015474 part 2: Add reftests for new "min-width:auto" sizing behavior on flex items. r=dbaron
Bug 1015474 part 3: Add reftests for new "min-height:auto" sizing behavior on flex items. r=dbaron

--HG--
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-001-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-001-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-001.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-001.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-002-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-002-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-002a.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-002a.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-002b.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-002b.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-002c.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-002c.html
Bug 1015474 part 4: Add reftests for interaction between "min-width:auto" & "overflow-x". r=dbaron
Bug 1015474 part 5: Add reftests for interaction between "min-[width|height]:auto" & "overflow-x"/"overflow-y". r=dbaron

--HG--
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-003-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-003.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-004-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-height-auto-004.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-004-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-003.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-min-width-auto-004.html
Bug 1015474 part 6: Remove tests for old "min-width:auto" behavior which are no longer correct (and/or obsoleted by newer tests). (no review)
Bug 1015474 part 7: Explicitly set min-[width|height]:0 on flex items, in flexbox-flex-flow-* reftests. (no review)
Bug 946167: crashtest for this bug. (no review)
bug 1036401 - adjust includes to fix up some issues with complete types instead of forward declarations being required r=bz r=bjacob
Bug 1039521 - nsTArray: Add an AppendElement take taking a r-value reference. r=froydnj

This lets us store UniquePtr's in nsTArrays

--HG--
extra : rebase_source : d7ea9ef710bd2451d0e2e9ba1aaefa9559315875
Bug 987040 - Part 4: mochitest for mozbrowserselectionchange api. r=ehsan
Bug 1040550 - Prevent MediaSource::SetDuration from being called outside the main thread. r=kinetik