[css-grid] Integrate baseline alignment into track sizing algorithm. First pass, issue #1039.

Author: fantasai

css-grid/Overview.bs

@@ -3745,6 +3745,11 @@ Resolve Intrinsic Track Sizes</h3>
 					furthermore clamp this <a>growth limit</a> by the ''fit-content()'' argument.
 			</dl>
 
+			<ins><p>In all cases, if any items participate in <a>baseline alignment</a>,
+			perform baseline alignment to calculate the extra space it would require,
+			and add that to the track’s <a>base size</a> and/or <a>growth limit</a>
+			as needed.</p></ins>
+
 			In all cases, if a track’s <a>growth limit</a> is now less than its <a>base size</a>,
 			increase the <a>growth limit</a> to match the <a>base size</a>.
 
@@ -3764,19 +3769,22 @@ Resolve Intrinsic Track Sizes</h3>
 					First increase the <a>base size</a> of tracks with
 					an <a lt="intrinsic sizing function">intrinsic</a> <a>min track sizing function</a>
 					by <a href="#extra-space">distributing extra space</a> as needed
-					to accommodate the contributions dictated by these items’ <a>min-size contributions</a>.
+					to accommodate these items’ <a>min-size contributions</a>
+					<ins>and <a>baseline alignment</a></ins>.
 				<li>
 					<strong>For content-based minimums:</strong>
 					Next continue to increase the <a>base size</a> of tracks with
 					a <a>min track sizing function</a> of ''min-content'' or ''max-content''
 					by <a href="#extra-space">distributing extra space</a> as needed
-					to account for these items' <a>min-content contributions</a>.
+					to account for these items' <a>min-content contributions</a>
+					<ins>and baseline alignment</ins>.
 				<li>
 					<strong>For max-content minimums:</strong>
 					Third continue to increase the <a>base size</a> of tracks with
 					a <a>min track sizing function</a> of ''max-content''
 					by <a href="#extra-space">distributing extra space</a> as needed
-					to account for these items' <a>max-content contributions</a>.
+					to account for these items' <a>max-content contributions</a>
+					<ins>and baseline alignment</ins>.
 				<li>
 					If at this point any track’s <a>growth limit</a> is now less than its <a>base size</a>,
 					increase its <a>growth limit</a> to match its <a>base size</a>.
@@ -3785,7 +3793,8 @@ Resolve Intrinsic Track Sizes</h3>
 					Next increase the <a>growth limit</a> of tracks with
 					an <a lt="intrinsic sizing function">intrinsic</a> <a>max track sizing function</a>
 					by <a href="#extra-space">distributing extra space</a> as needed
-					to account for these items' <a>min-size contributions</a>.
+					to account for these items' <a>min-size contributions</a>
+					<ins>and baseline alignment</ins>.
 					Mark any tracks whose <a>growth limit</a> changed
 					from infinite to finite in this step
 					as <dfn>infinitely growable</dfn> for the next step.
@@ -3834,7 +3843,8 @@ Resolve Intrinsic Track Sizes</h3>
 					Lastly continue to increase the <a>growth limit</a> of tracks with
 					a <a>max track sizing function</a> of ''max-content''
 					by <a href="#extra-space">distributing extra space</a> as needed
-					to account for these items' <a>max-content contributions</a>.
+					to account for these items' <a>max-content contributions</a>
+					<ins>and baseline alignment</ins>.
 					However, limit the growth of any ''fit-content()'' tracks
 					by their ''fit-content()'' argument.
 			</ol>
@@ -3913,6 +3923,14 @@ Resolve Intrinsic Track Sizes</h3>
 			</ol>
 	</ol>
 
+	<ins><p>The extra space required to accommodate
+	an item’s participation in <a>baseline alignment</a>
+	is distributed by
+	calculating the shims required for including their participation
+	with already-considered items (those of lesser or equal spanning size)
+	and distributing the shims’ space as if it were
+	part of the shimmed items’ original size contribution.</p></ins>
+
 	Note: When this step is complete,
 	all intrinsic <a>base sizes</a> and <a>growth limits</a>
 	will have been resolved to absolute lengths.