Implement ConsumeShorthandViaLonghand to parse shorthand by calling longhand ParseSingleValue

third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
index c21a17aebd834fa25cb8d8ba7f89d1473ed2f51e..e5ea4aa69be8a6d1e0b80ee0e032b8f69f444edb 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
@@ -1884,34 +1884,98 @@ bool CSSPropertyParser::ConsumeColumns(bool important) {
 bool CSSPropertyParser::ConsumeShorthandGreedily(
     const StylePropertyShorthand& shorthand,
     bool important) {
+  return ConsumeShorthandViaLonghand(shorthand, important,
+                                     LonghandsOrder::kNoOrder);
+}
+
+bool CSSPropertyParser::ConsumeShorthandViaLonghand(
+    const StylePropertyShorthand& shorthand,
+    bool important,
+    LonghandsOrder order) {
   // Existing shorthands have at most 6 longhands.
   DCHECK_LE(shorthand.length(), 6u);
+
+  const bool ordered_parsing = order != LonghandsOrder::kNoOrder;
+
   const CSSValue* longhands[6] = {nullptr, nullptr, nullptr,
                                   nullptr, nullptr, nullptr};
+
   const CSSPropertyID* shorthand_properties = shorthand.properties();
-  do {
+
+  if (range_.AtEnd()) {
+    return false;
+  }
+
+  // Only set "next" to the next ordered longhand. It will remain 0 for
+  // unordered case.
+  size_t next = 0;
+  // For ordered longhands only. It becomes false when the parser fails to parse
+  // a longhand. In this case, we want to stop subsequent parsing immediately.
+  bool continue_parsing = true;
+
+  while (!range_.AtEnd()) {
+    size_t i = next;
     bool found_longhand = false;
-    for (size_t i = 0; !found_longhand && i < shorthand.length(); ++i) {
-      if (longhands[i])
+
+    while (i < shorthand.length() && continue_parsing) {
+      if (longhands[i]) {
+        DCHECK(!ordered_parsing);
+        ++i;
         continue;
+      }
       longhands[i] = ParseSingleValue(shorthand_properties[i], shorthand.id());
-      if (longhands[i])
+      if (longhands[i]) {
         found_longhand = true;
+        if (ordered_parsing) {
+          ++next;
+        }
+        break;
+      }
+      if (ordered_parsing) {
+        if (i == 0) {
+          return false;
+        }
+        continue_parsing = false;
+        break;
+      }
+      ++i;
     }
-    if (!found_longhand)
+
+    if (!found_longhand && !ordered_parsing) {
       return false;
-  } while (!range_.AtEnd());
+    }
+    if (!continue_parsing || next == shorthand.length()) {
+      DCHECK_GT(next, 0u);
+      break;
+    }
+  }
+
+  if (ordered_parsing) {
+    DCHECK(longhands[0]);
+  }
+
+  std::map<size_t, size_t> default_property_index = {{1u, 0}};
+  if (order == LonghandsOrder::kOrderBy4Values) {
+    default_property_index[2u] = 0;
+    default_property_index[3u] = 1u;
+  }
 
   for (size_t i = 0; i < shorthand.length(); ++i) {
-    if (longhands[i]) {
-      AddParsedProperty(shorthand_properties[i], shorthand.id(), *longhands[i],
-                        important);
-    } else {
-      AddParsedProperty(shorthand_properties[i], shorthand.id(),
-                        *CSSInitialValue::Create(), important);
+    if (!longhands[i]) {
+      if (ordered_parsing) {
+        std::map<size_t, size_t>::iterator iter =
+            default_property_index.find(i);
+        DCHECK(iter != default_property_index.end());
+        longhands[i] = longhands[iter->second];
+      } else {
+        longhands[i] = CSSInitialValue::Create();
+      }
     }
+    AddParsedProperty(shorthand_properties[i], shorthand.id(), *longhands[i],
+                      important);
   }
-  return true;
+
+  return range_.AtEnd();
 }
 
 bool CSSPropertyParser::ConsumeFlex(bool important) {
@@ -2027,51 +2091,14 @@ bool CSSPropertyParser::ConsumeBorder(bool important) {
 
 bool CSSPropertyParser::Consume2Values(const StylePropertyShorthand& shorthand,
                                        bool important) {
-  DCHECK_EQ(shorthand.length(), 2u);
-  const CSSPropertyID* longhands = shorthand.properties();
-  const CSSValue* start = ParseSingleValue(longhands[0], shorthand.id());
-  if (!start)
-    return false;
-
-  const CSSValue* end = ParseSingleValue(longhands[1], shorthand.id());
-  if (!end)
-    end = start;
-  AddParsedProperty(longhands[0], shorthand.id(), *start, important);
-  AddParsedProperty(longhands[1], shorthand.id(), *end, important);
-
-  return range_.AtEnd();
+  return ConsumeShorthandViaLonghand(shorthand, important,
+                                     LonghandsOrder::kOrderBy2Values);
 }
 
 bool CSSPropertyParser::Consume4Values(const StylePropertyShorthand& shorthand,
                                        bool important) {
-  DCHECK_EQ(shorthand.length(), 4u);
-  const CSSPropertyID* longhands = shorthand.properties();
-  const CSSValue* top = ParseSingleValue(longhands[0], shorthand.id());
-  if (!top)
-    return false;
-
-  const CSSValue* right = ParseSingleValue(longhands[1], shorthand.id());
-  const CSSValue* bottom = nullptr;
-  const CSSValue* left = nullptr;
-  if (right) {
-    bottom = ParseSingleValue(longhands[2], shorthand.id());
-    if (bottom)
-      left = ParseSingleValue(longhands[3], shorthand.id());
-  }
-
-  if (!right)
-    right = top;
-  if (!bottom)
-    bottom = top;
-  if (!left)
-    left = right;
-
-  AddParsedProperty(longhands[0], shorthand.id(), *top, important);
-  AddParsedProperty(longhands[1], shorthand.id(), *right, important);
-  AddParsedProperty(longhands[2], shorthand.id(), *bottom, important);
-  AddParsedProperty(longhands[3], shorthand.id(), *left, important);
-
-  return range_.AtEnd();
+  return ConsumeShorthandViaLonghand(shorthand, important,
+                                     LonghandsOrder::kOrderBy4Values);
 }
 
 // TODO(crbug.com/668012): refactor out property specific logic from this method