[CSS Grid Layout] Fix grid-template-areas parsing to avoid spaces

Source/core/css/parser/CSSPropertyParser.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 3654 matching lines @@
 
         return cssValuePool().createValue(flexValue, CSSPrimitiveValue::CSS_FR);
     }
 
     if (!validUnit(currentValue, FNonNeg | FLength | FPercent))
         return nullptr;
 
     return createPrimitiveNumericValue(currentValue);
 }
 
-static bool containsOnlyDots(const String& string)
+static Vector<String> parseGridTemplateAreasColumnNames(const String& gridRowNames)
 {
-    ASSERT(!string.isEmpty());
-    StringImpl& text = *string.impl();
+    ASSERT(!gridRowNames.isEmpty());
+    Vector<String> columnNames;
+    StringImpl& text = *gridRowNames.impl();

[Julien - ping for review, 2015/06/10 15:31:18]

I would like a comment for this. I assume this is because you want to avoid
NULL-checking the StringImpl all the time in WTFString::operator[].

[Manuel Rego, 2015/06/10 20:41:45]

Yes. Added a comment.

+
+    String areaName = "";

[Julien - ping for review, 2015/06/10 15:31:18]

You want to use StringBuilder to avoid unneeded buffer copies, which will kill
performance.

[Manuel Rego, 2015/06/10 20:41:45]

Done.

     for (unsigned i = 0; i < text.length(); ++i) {
-        if (text[i] != '.')
-            return false;
+        if (text[i] == ' ') {
+            if (!areaName.isEmpty()) {
+                columnNames.append(areaName);
+                areaName = "";
+            }
+            continue;
+        }
+        if (text[i] == '.') {
+            if (areaName == ".")
+                continue;
+            if (!areaName.isEmpty()) {
+                columnNames.append(areaName);
+                areaName = "";
+            }
+        } else {
+            if (areaName == ".") {
+                columnNames.append(areaName);
+                areaName = "";
+            }
+        }
+
+        areaName.append(text[i]);
     }
-    return true;
+
+    if (!areaName.isEmpty())
+        columnNames.append(areaName);
+
+    return columnNames;
 }
 
 bool CSSPropertyParser::parseGridTemplateAreasRow(NamedGridAreaMap& gridAreaMap, const size_t rowCount, size_t& columnCount)
 {
     CSSParserValue* currentValue = m_valueList->current();
     if (!currentValue || currentValue->unit != CSSPrimitiveValue::CSS_STRING)
         return false;
 
     String gridRowNames = currentValue->string;
     if (gridRowNames.isEmpty() || gridRowNames.containsOnlyWhitespace())
         return false;
 
-    Vector<String> columnNames;
-    gridRowNames.split(' ', columnNames);
-
+    Vector<String> columnNames = parseGridTemplateAreasColumnNames(gridRowNames);
     if (!columnCount) {
         columnCount = columnNames.size();
         ASSERT(columnCount);
     } else if (columnCount != columnNames.size()) {
         // The declaration is invalid is all the rows don't have the number of columns.
         return false;
     }
 
     for (size_t currentCol = 0; currentCol < columnCount; ++currentCol) {
         const String& gridAreaName = columnNames[currentCol];
 
         // Unamed areas are always valid (we consider them to be 1x1).
-        if (containsOnlyDots(gridAreaName))
+        if (gridAreaName == ".")
             continue;
 
         // We handle several grid areas with the same name at once to simplify the validation code.
         size_t lookAheadCol;
         for (lookAheadCol = currentCol; lookAheadCol < (columnCount - 1); ++lookAheadCol) {
             if (columnNames[lookAheadCol + 1] != gridAreaName)
                 break;
         }
 
         NamedGridAreaMap::iterator gridAreaIt = gridAreaMap.find(gridAreaName);
@@ skipping 4755 matching lines @@
         }
     }
 
     if (!list->length())
         return nullptr;
 
     return list.release();
 }
 
 } // namespace blink