Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

LayoutTests/platform/mac/fast/regions/top-overflow-out-of-second-region-expected.txt

Index: LayoutTests/platform/mac/fast/regions/top-overflow-out-of-second-region-expected.txt
diff --git a/LayoutTests/platform/mac/fast/regions/top-overflow-out-of-second-region-expected.txt b/LayoutTests/platform/mac/fast/regions/top-overflow-out-of-second-region-expected.txt
deleted file mode 100644
index f824a7562cc252801f77338c151d8880777a4412..0000000000000000000000000000000000000000
--- a/LayoutTests/platform/mac/fast/regions/top-overflow-out-of-second-region-expected.txt
+++ /dev/null
@@ -1,44 +0,0 @@
-layer at (0,0) size 800x600
-  RenderView at (0,0) size 800x600
-layer at (0,0) size 800x418
-  RenderBlock {HTML} at (0,0) size 800x418
-    RenderBody {BODY} at (8,16) size 784x394
-      RenderBlock {P} at (0,0) size 784x72
-        RenderText {#text} at (0,0) size 779x72
-          text run at (0,0) width 775: "In the test case below, the green block's width should not vary and should use the second region to determine its width. It is"
-          text run at (0,18) width 731: "overflowing upwards out of the blue block, and so the portion that overflows should continue to use the blue block's"
-          text run at (0,36) width 779: "containing block width. The blue block does not exist in region one, so using some hypothetical made-up width is incorrect."
-          text run at (0,54) width 565: "The overflow should be spilling out of the top of region two and be painted in region one."
-      RenderBlock {DIV} at (0,88) size 784x306
-layer at (8,104) size 302x102
-  RenderBlock {DIV} at (0,0) size 302x102 [border: (1px solid #000000)]
-    RenderNamedFlowFragment at (1,1) size 300x100
-layer at (8,206) size 402x202
-  RenderBlock {DIV} at (0,102) size 402x202 [border: (1px solid #000000)]
-    RenderNamedFlowFragment at (1,1) size 400x200
-layer at (8,408) size 2x2
-  RenderBlock {DIV} at (0,304) size 2x2 [border: (1px solid #000000)]
-    RenderNamedFlowFragment at (1,1) size 0x0
-Named flows
-  Named flow 'flow1'
-    layer at (0,0) size 400x300
-      RenderNamedFlowThread at (0,0) size 400x300
-        RenderBlock {DIV} at (0,0) size 400x177
-          RenderBlock {DIV} at (5,100) size 390x72 [border: (1px solid #0000FF)]
-            RenderBlock {DIV} at (48.50,-99) size 293x170 [border: (1px solid #008000)]
-              RenderBlock {P} at (1,17) size 291x54
-                RenderText {#text} at (0,0) size 291x54
-                  text run at (0,0) width 291: "These lines should all fit to the width of the"
-                  text run at (0,18) width 291: "block in the second region and spill out of the"
-                  text run at (0,36) width 112: "top of the second "
-                  text run at (112,36) width 44: "region."
-              RenderBlock {P} at (1,99) size 291x54
-                RenderText {#text} at (0,0) size 291x54
-                  text run at (0,0) width 291: "These lines should all fit to the width of the"
-                  text run at (0,18) width 291: "block in the second region and spill out of the"
-                  text run at (0,36) width 112: "top of the second "
-                  text run at (112,36) width 44: "region."
-    Regions for named flow 'flow1'
-      RenderNamedFlowFragment (anonymous child of {DIV} #region1)
-      RenderNamedFlowFragment (anonymous child of {DIV} #region2)
-      RenderNamedFlowFragment (anonymous child of {DIV} #region3)