LibWeb: Remove "temporary content size" hack from flex layout

This was an old hack intended to make percentage sizes on flex items
before we had implemented the appropriate special behavior of definite
sizes in flex layout.

Removing it makes flex layout less magical and should not change
behavior in any observable way.

Libraries/LibWeb/Layout/FlexFormattingContext.cpp

@@ -675,17 +675,6 @@ void FlexFormattingContext::determine_flex_base_size_and_hypothetical_main_size(
     auto clamp_min = has_main_min_size(child_box) ? specified_main_min_size(child_box) : automatic_minimum_size(item);
     auto clamp_max = has_main_max_size(child_box) ? specified_main_max_size(child_box) : CSSPixels::max();
     item.hypothetical_main_size = max(CSSPixels(0), css_clamp(item.flex_base_size, clamp_min, clamp_max));
-
-    // NOTE: At this point, we set the hypothetical main size as the flex item's *temporary* main size.
-    //       The size may change again when we resolve flexible lengths, but this is necessary in order for
-    //       descendants of this flex item to resolve percentage sizes against something.
-    //
-    //       The spec just barely hand-waves about this, but it seems to *roughly* match what other engines do.
-    //       See "Note" section here: https://drafts.csswg.org/css-flexbox-1/#definite-sizes
-    if (is_row_layout())
-        item.used_values.set_temporary_content_width(item.hypothetical_main_size);
-    else
-        item.used_values.set_temporary_content_height(item.hypothetical_main_size);
 }
 
 // https://drafts.csswg.org/css-flexbox-1/#min-size-auto

Libraries/LibWeb/Layout/LayoutState.cpp

@@ -648,16 +648,6 @@ void LayoutState::UsedValues::set_content_height(CSSPixels height)
     m_content_height = clamp_to_max_dimension_value(height);
 }
 
-void LayoutState::UsedValues::set_temporary_content_width(CSSPixels width)
-{
-    m_content_width = clamp_to_max_dimension_value(width);
-}
-
-void LayoutState::UsedValues::set_temporary_content_height(CSSPixels height)
-{
-    m_content_height = height;
-}
-
 AvailableSize LayoutState::UsedValues::available_width_inside() const
 {
     if (width_constraint == SizeConstraint::MinContent)

Libraries/LibWeb/Layout/LayoutState.h

@@ -88,11 +88,6 @@ struct LayoutState {
         void set_has_definite_width(bool has_definite_width) { m_has_definite_width = has_definite_width; }
         void set_has_definite_height(bool has_definite_height) { m_has_definite_height = has_definite_height; }
 
-        // NOTE: These are used by FlexFormattingContext to assign a temporary main size to items
-        //       early on, so that descendants have something to resolve percentages against.
-        void set_temporary_content_width(CSSPixels);
-        void set_temporary_content_height(CSSPixels);
-
         bool has_definite_width() const { return m_has_definite_width && width_constraint == SizeConstraint::None; }
         bool has_definite_height() const { return m_has_definite_height && height_constraint == SizeConstraint::None; }