Bug 984711 part 1: Revert tweaks to unit tests, now that 'min-width:auto' support is coming back. (no review; just an unbitrotted backout)

This reverts changeset afe27d80eeef from bug 848539.
Bug 984711 part 2: Add back min-width:auto & min-height:auto in the parser and as default value (just computing to '0' for now). (no review; just an unbitrotted backout)

This reverts changeset e7a9e30409eb from bug 848539.
Bug 984711 part 3: Add back handling for nsStylePosition::mMinWidth having "eStyleUnit_Auto" in style system & general layout code. (no review; just an unbitrotted backout)

This reverts changeset f8b5090d02e5 from bug 848539.
Bug 984711 part 4: Add back handling for nsStylePosition::mMinHeight having "eStyleUnit_Auto" in style system & general layout code. (no review; just an unbitrotted backout)

This reverts changeset 5db313632268 from bug 848539.
Bug 984711 part 5: Add back handling for min-height:auto to nsFlexContainerFrame. r=mats

This conceptually reverts changeset 7a289f49170f from bug 848539, though the code being modified looks a bit different now.
Bug 984711 part 6: Add back special handling for min-width:auto in nsHTMLReflowState & getComputedStyle. (no review; just an unbitrotted backout)

This reverts changeset 1eae876d6c3a from bug 848539.
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)