Attempt to clean up requiresLayoutToDetermineWidth to be more clear

Source/core/rendering/RenderBox.cpp

Index: Source/core/rendering/RenderBox.cpp
diff --git a/Source/core/rendering/RenderBox.cpp b/Source/core/rendering/RenderBox.cpp
index b0cd4d79b14e72a0f184c0a89d600c638d763fe2..1b9064a62ad47674a8ea5908ae6785750fea57a7 100644
--- a/Source/core/rendering/RenderBox.cpp
+++ b/Source/core/rendering/RenderBox.cpp
@@ -408,26 +408,31 @@ int RenderBox::pixelSnappedOffsetHeight() const
     return snapSizeToPixel(offsetHeight(), y() + clientTop());
 }
 
-bool RenderBox::requiresLayoutToDetermineWidth() const
-{
-    RenderStyle* style = this->style();
-    return !style->width().isFixed()
-        || !style->minWidth().isFixed()
-        || (!style->maxWidth().isUndefined() && !style->maxWidth().isFixed())
-        || !style->paddingLeft().isFixed()
-        || !style->paddingRight().isFixed()
-        || style->resize() != RESIZE_NONE
-        || style->boxSizing() == BORDER_BOX
-        || !isRenderBlock()
-        || !isRenderBlockFlow()
+bool RenderBox::canDetermineWidthWithoutLayout() const
+{
+    // FIXME: There are likely many subclasses of RenderBlockFlow which

[Julien - ping for review, 2013/09/30 16:28:06]

Maybe also classes outside RenderBlockFlow?

+    // cannot determine their layout just from style!
+    // Perhaps we should create a "PlainRenderBlockFlow"
+    // and move this optimization there?
+    if (!isRenderBlockFlow()
+        // Flexbox items can be expanded beyond their width.
         || isFlexItemIncludingDeprecated()
-        // TableCells can expand beyond a specified width.
-        || isTableCell();
+        // Table Layout controls cell size, width is ignored.

[Julien - ping for review, 2013/09/30 16:28:06]

width is not ignored when doing a table layout. On the contrary, it is used to
determine the cell's width. What is important is that the table layout algorithm
can override the computed width, which is why we have to run layout.

+        || isTableCell())
+        return false;
+
+    RenderStyle* style = this->style();
+    return style->width().isFixed()
+        && style->minWidth().isFixed()
+        && (style->maxWidth().isUndefined() || style->maxWidth().isFixed())
+        && style->paddingLeft().isFixed()
+        && style->paddingRight().isFixed()
+        && style->boxSizing() == CONTENT_BOX;
 }
 
 LayoutUnit RenderBox::fixedOffsetWidth() const
 {
-    ASSERT(!requiresLayoutToDetermineWidth());
+    ASSERT(canDetermineWidthWithoutLayout());
 
     RenderStyle* style = this->style();
 
@@ -2088,7 +2093,9 @@ static float getMaxWidthListMarker(const RenderBox* renderer)
             if (!itemChild->isListMarker())
                 continue;
             RenderBox* itemMarker = toRenderBox(itemChild);
-            if (itemMarker->requiresLayoutToDetermineWidth() && itemMarker->needsLayout()) {
+            // FIXME: canDetermineWidthWithoutLayout expects us to use fixedOffsetWidth, which this code
+            // does not do! This check is likely wrong.
+            if (!itemMarker->canDetermineWidthWithoutLayout() && itemMarker->needsLayout()) {
                 // Make sure to compute the autosized width.
                 itemMarker->layout();

[Julien - ping for review, 2013/09/30 16:28:06]

layoutIfNeeded()?

             }