Revert "[LayoutNG] Support non-horizontal flows in Flexbox"

This reverts commit 7fbb7857.

Reason for revert: Persistent failures on https://ci.chromium.org/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20ASAN/ - see https://crbug.com/909021

Original change's description:
> [LayoutNG] Support non-horizontal flows in Flexbox
> 
> Meaning: column containers, ortho children, and non-horizontal
> writing modes
> 
> Bug: 845235
> Change-Id: Iba6525752d0c14a77bc9a13cc75a484cdf3a711d
> Reviewed-on: https://chromium-review.googlesource.com/c/1332247
> Commit-Queue: David Grogan <dgrogan@chromium.org>
> Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#611268}

TBR=cbiesinger@chromium.org,dgrogan@chromium.org

Change-Id: Ib66afedb725af13acd85a298c4fd565f02b32019
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 845235,909021
Reviewed-on: https://chromium-review.googlesource.com/c/1352670Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#611402}

third_party/blink/renderer/core/layout/flexible_box_algorithm.h

@@ -67,7 +67,6 @@ typedef Vector<FlexItem, 8> FlexItemVector;
 class FlexItem {
  public:
   // flex_base_content_size includes scrollbar width but not border or padding.
-  // min_max_sizes is the min and max size in the main axis direction.
   FlexItem(LayoutBox*,
            LayoutUnit flex_base_content_size,
            MinMaxSize min_max_sizes,

third_party/blink/renderer/core/layout/ng/ng_flex_layout_algorithm.h

@@ -29,18 +29,6 @@ class CORE_EXPORT NGFlexLayoutAlgorithm
 
   base::Optional<MinMaxSize> ComputeMinMaxSize(
       const MinMaxSizeInput&) const override;
-
- private:
-  // This is same method as FlexItem but we need that logic before FlexItem is
-  // constructed.
-  bool MainAxisIsInlineAxis(NGBlockNode child);
-  LayoutUnit MainAxisContentExtent(LayoutUnit sum_hypothetical_main_size);
-
-  NGLogicalSize border_box_size_;
-  NGBoxStrut border_scrollbar_padding_;
-  NGLogicalSize content_box_size_;
-  NGBoxStrut borders_;
-  NGBoxStrut padding_;
 };
 
 }  // namespace blink

third_party/blink/renderer/core/layout/ng/ng_length_utils.h

@@ -130,11 +130,10 @@ MinMaxSize ComputeMinAndMaxContentContribution(
     NGLayoutInputNode child,
     const MinMaxSizeInput& input);
 
-// Returns inline size of the node's border box by resolving the computed value
-// in style.logicalWidth (Length) to a layout unit, adding border and padding,
-// then constraining the result by the resolved min logical width and max
-// logical width from the ComputedStyle object. Calls Node::ComputeMinMaxSize if
-// needed. override_minmax is provided *solely* for use by unit tests.
+// Resolves the computed value in style.logicalWidth (Length) to a layout unit,
+// then constrains the result by the resolved min logical width and max logical
+// width from the ComputedStyle object. Calls Node::ComputeMinMaxSize if needed.
+// override_minmax is provided *solely* for use by unit tests.
 // border_padding can be passed in as an optimization; otherwise this function
 // will compute it itself.
 CORE_EXPORT LayoutUnit ComputeInlineSizeForFragment(