Issue #1230 - Part 1: Fix Back-computing percentages for intrinsic sizing in Layout CSS-Grid

List of relevant patches applied:

1398537 part 2 - [css-multicol] Implement percentages for 'column-gap' (Gecko part).

1434478 part 1 - [css-grid] Stop back-computing percentage grid gaps when the percentage basis is indefinite. Treat them as zero sized instead.

1434478 part 2 - Stop back-computing percentage padding/margin when the percentage basis is indefinite. Treat them as zero sized instead.

1434478 part 3 - Remove IntrinsicISizeOffsetData::hPctPadding/hPctMargin members since they are now unused.

1434478 part 4 - Factor out constants like NS_UNCONSTRAINEDSIZE so they can be used in headers without needing nsIFrame.h (idempotent patch).

1434478 part 5 - Create nsLayoutUtils::ResolveToLength for resolving CSS <length-percentage> (idempotent patch).

1434478 part 6 - Propagate a percentage basis to nsIFrame::IntrinsicISizeOffsets for resolving padding/margin.

This is needed only for CSS Grid since in other cases we're only using IntrinsicISizeOffsets in the inline-axis and the percentage basis is always indefinite for *intrinsic sizing*. When calculating the intrinsic size of grid items in the grid container's block axis however, we do have a definite size for the grid area in the inline-axis and it should be used per: https://drafts.csswg.org/css-grid/#algo-overview "2. Next, the track sizing algorithm resolves the sizes of the grid rows, using the grid column sizes calculated in the previous step." (Percentage padding/margin for grid items is always resolved against the grid area's inline-size nowadays.)

4 files changed, 10 insertions, 9 deletions

diff --git a/layout/tables/nsTableCellFrame.cpp b/layout/tables/nsTableCellFrame.cpp
index 316a96613..dea82ea59 100644
--- a/layout/tables/nsTableCellFrame.cpp
+++ b/layout/tables/nsTableCellFrame.cpp
@@ -796,12 +796,12 @@ nsTableCellFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
 }
 
 /* virtual */ nsIFrame::IntrinsicISizeOffsetData
-nsTableCellFrame::IntrinsicISizeOffsets()
+nsTableCellFrame::IntrinsicISizeOffsets(nscoord aPercentageBasis)
 {
-  IntrinsicISizeOffsetData result = nsContainerFrame::IntrinsicISizeOffsets();
+  IntrinsicISizeOffsetData result =
+    nsContainerFrame::IntrinsicISizeOffsets(aPercentageBasis);
 
   result.hMargin = 0;
-  result.hPctMargin = 0;
 
   WritingMode wm = GetWritingMode();
   result.hBorder = GetBorderWidth(wm).IStartEnd(wm);
diff --git a/layout/tables/nsTableCellFrame.h b/layout/tables/nsTableCellFrame.h
index 6717e1b70..240809850 100644
--- a/layout/tables/nsTableCellFrame.h
+++ b/layout/tables/nsTableCellFrame.h
@@ -118,7 +118,8 @@ public:
 
   virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) override;
   virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) override;
-  virtual IntrinsicISizeOffsetData IntrinsicISizeOffsets() override;
+  IntrinsicISizeOffsetData IntrinsicISizeOffsets(nscoord aPercentageBasis =
+                                                 NS_UNCONSTRAINEDSIZE) override;
 
   virtual void Reflow(nsPresContext*      aPresContext,
                       ReflowOutput& aDesiredSize,
diff --git a/layout/tables/nsTableFrame.cpp b/layout/tables/nsTableFrame.cpp
index b9b6ca5fe..272a77406 100644
--- a/layout/tables/nsTableFrame.cpp
+++ b/layout/tables/nsTableFrame.cpp
@@ -1564,16 +1564,15 @@ nsTableFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
 }
 
 /* virtual */ nsIFrame::IntrinsicISizeOffsetData
-nsTableFrame::IntrinsicISizeOffsets()
+nsTableFrame::IntrinsicISizeOffsets(nscoord aPercentageBasis)
 {
-  IntrinsicISizeOffsetData result = nsContainerFrame::IntrinsicISizeOffsets();
+  IntrinsicISizeOffsetData result =
+    nsContainerFrame::IntrinsicISizeOffsets(aPercentageBasis);
 
   result.hMargin = 0;
-  result.hPctMargin = 0;
 
   if (IsBorderCollapse()) {
     result.hPadding = 0;
-    result.hPctPadding = 0;
 
     WritingMode wm = GetWritingMode();
     LogicalMargin outerBC = GetIncludedOuterBCBorder(wm);
diff --git a/layout/tables/nsTableFrame.h b/layout/tables/nsTableFrame.h
index 7e56c28c1..c7b92d387 100644
--- a/layout/tables/nsTableFrame.h
+++ b/layout/tables/nsTableFrame.h
@@ -324,7 +324,8 @@ public:
   // border to the results of these functions.
   virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) override;
   virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) override;
-  virtual IntrinsicISizeOffsetData IntrinsicISizeOffsets() override;
+  IntrinsicISizeOffsetData IntrinsicISizeOffsets(nscoord aPercentageBasis =
+                                                 NS_UNCONSTRAINEDSIZE) override;
 
   virtual mozilla::LogicalSize
   ComputeSize(nsRenderingContext*         aRenderingContext,