[CSSGridLayout] Resolved value of grid-template-* to include every track

Source/core/css/CSSComputedStyleDeclaration.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ skipping 869 matching lines @@
     RefPtrWillBeRawPtr<CSSGridLineNamesValue> lineNames = CSSGridLineNamesValue::create();
     for (size_t j = 0; j < namedGridLines.size(); ++j)
         lineNames->append(cssValuePool().createValue(namedGridLines[j], CSSPrimitiveValue::CSS_STRING));
     list.append(lineNames.release());
 }
 
 static PassRefPtrWillBeRawPtr<CSSValue> valueForGridTrackList(GridTrackSizingDirection direction, RenderObject* renderer, const RenderStyle& style)
 {
     const Vector<GridTrackSize>& trackSizes = direction == ForColumns ? style.gridTemplateColumns() : style.gridTemplateRows();
     const OrderedNamedGridLines& orderedNamedGridLines = direction == ForColumns ? style.orderedNamedGridColumnLines() : style.orderedNamedGridRowLines();
+    bool isRenderGrid = renderer && renderer->isRenderGrid();
 
-    // Handle the 'none' case here.
-    if (!trackSizes.size()) {
+    // Handle the 'none' case.
+    bool trackListIsEmpty = trackSizes.isEmpty();
+    if (isRenderGrid && trackListIsEmpty) {
+        // For grids we should consider every listed track, whether implicitly or explicitly created. If we don't have
+        // any explicit track and there are no children then there are no implicit tracks. We cannot simply check the
+        // number of rows/columns in our internal grid representation because it's always at least 1x1 (see r143331).
+        trackListIsEmpty = !toRenderBlock(renderer)->firstChild();
+    }
+
+    if (trackListIsEmpty) {
         ASSERT(orderedNamedGridLines.isEmpty());
         return cssValuePool().createIdentifierValue(CSSValueNone);
     }
 
     RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createSpaceSeparated();
-    if (renderer && renderer->isRenderGrid()) {
+    if (isRenderGrid) {
         const Vector<LayoutUnit>& trackPositions = direction == ForColumns ? toRenderGrid(renderer)->columnPositions() : toRenderGrid(renderer)->rowPositions();
         // There are at least #tracks + 1 grid lines (trackPositions). Apart from that, the grid container can generate implicit grid tracks,
         // so we'll have more trackPositions than trackSizes as the latter only contain the explicit grid.
         ASSERT(trackPositions.size() - 1 >= trackSizes.size());
 
-        for (size_t i = 0; i < trackSizes.size(); ++i) {
+        for (size_t i = 0; i < trackPositions.size() - 1; ++i) {
             addValuesForNamedGridLinesAtIndex(orderedNamedGridLines, i, *list);
             list->append(zoomAdjustedPixelValue(trackPositions[i + 1] - trackPositions[i], style));
         }
     } else {
         for (size_t i = 0; i < trackSizes.size(); ++i) {
             addValuesForNamedGridLinesAtIndex(orderedNamedGridLines, i, *list);
             list->append(specifiedValueForGridTrackSize(trackSizes[i], style));
         }
     }
     // Those are the trailing <string>* allowed in the syntax.
@@ skipping 2093 matching lines @@
     return list.release();
 }
 
 void CSSComputedStyleDeclaration::trace(Visitor* visitor)
 {
     visitor->trace(m_node);
     CSSStyleDeclaration::trace(visitor);
 }
 
 } // namespace blink