[css-grid] Clarify that step 2.2 of the 'distribute extra space' algo doesn't do anything to growth limits.

Author: tabatkins

css-grid/Overview.bs

@@ -2769,19 +2769,25 @@ Resolve Content-Based Track Sizing Functions</h3>
 					(For infinite <i>growth limits</i>, substitute the track's <i>base size</i>.)
 					This is the space to distribute. Floor it at zero.
 					<pre><var>extra-space</var> = max(0, <var>size-contribution</var> - ∑<var>track-sizes</var>)</pre>
+
 				<li>
-				  <strong>Distribute space up to growth limits:</strong>
+					<strong>Distribute space to base sizes up to growth limits:</strong>
 					Distribute the space equally to the planned increase of each spanned track with an affected size,
 					freezing tracks as their planned size reaches their <i>growth limits</i>
 					(and continuing to grow the unfrozen tracks as needed).
 
 					If a track was marked as infinitely growable for this phase,
 					treat its <i>growth limit</i> as infinite for this calculation
 					(and then unmark it).
+
+					Note: If the affected size was a <a>growth limit</a>,
+					this step has no effect.
+
 				<li>
 					<strong>Distribute space beyond growth limits:</strong>
 					If space remains after all tracks are frozen,
-					unfreeze and continue to distribute space to&hellip;
+					unfreeze and continue to distribute space to…
+
 					<ul>
 						<li>
 							when handling ''min-content'' <i>base sizes</i>:

css-grid/Overview.html

@@ -2821,19 +2821,25 @@ <h3 class="heading settled heading" data-level=10.4 id=algo-content><span class=
 					(For infinite <a data-link-type=dfn href=#growth-limit title="growth limits">growth limits</a>, substitute the track’s <a data-link-type=dfn href=#base-size title="base size">base size</a>.)
 					This is the space to distribute. Floor it at zero.
 <pre><var>extra-space</var> = max(0, <var>size-contribution</var> - ∑<var>track-sizes</var>)</pre>
+
 				<li>
-				  <strong>Distribute space up to growth limits:</strong>
+					<strong>Distribute space to base sizes up to growth limits:</strong>
 					Distribute the space equally to the planned increase of each spanned track with an affected size,
 					freezing tracks as their planned size reaches their <a data-link-type=dfn href=#growth-limit title="growth limits">growth limits</a>
 					(and continuing to grow the unfrozen tracks as needed).
 
 <p>If a track was marked as infinitely growable for this phase,
 					treat its <a data-link-type=dfn href=#growth-limit title="growth limit">growth limit</a> as infinite for this calculation
 					(and then unmark it).</p>
+
+<p class=note>Note: If the affected size was a <a data-link-type=dfn href=#growth-limit title="growth limit">growth limit</a>,
+					this step has no effect.</p>
+
 				<li>
 					<strong>Distribute space beyond growth limits:</strong>
 					If space remains after all tracks are frozen,
 					unfreeze and continue to distribute space to…
+
 					<ul>
 						<li>
 							when handling <a class=css data-link-type=maybe href=#valuedef-min-content title=min-content>min-content</a> <a data-link-type=dfn href=#base-size title="base sizes">base sizes</a>: