Make CSSParserContext be garbage collected.

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

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParser.h
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.h b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.h
index d886266675116cbf3a90e6d768eb49991dae2c1d..66377f75fafa393e838f1b9ff07c061718ad7491 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.h
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.h
@@ -47,18 +47,18 @@ class CSSPropertyParser {
   static bool parseValue(CSSPropertyID,
                          bool important,
                          const CSSParserTokenRange&,
-                         const CSSParserContext&,
+                         const CSSParserContext*,
                          HeapVector<CSSProperty, 256>&,
                          StyleRule::RuleType);
 
   // Parses a non-shorthand CSS property
   static const CSSValue* parseSingleValue(CSSPropertyID,
                                           const CSSParserTokenRange&,
-                                          const CSSParserContext&);
+                                          const CSSParserContext*);
 
  private:
   CSSPropertyParser(const CSSParserTokenRange&,
-                    const CSSParserContext&,
+                    const CSSParserContext*,
                     HeapVector<CSSProperty, 256>*);
 
   // TODO(timloh): Rename once the CSSParserValue-based parseValue is removed
@@ -67,7 +67,7 @@ class CSSPropertyParser {
   const CSSValue* parseSingleValue(CSSPropertyID,
                                    CSSPropertyID = CSSPropertyInvalid);
 
-  bool inQuirksMode() const { return isQuirksModeBehavior(m_context.mode()); }
+  bool inQuirksMode() const { return isQuirksModeBehavior(m_context->mode()); }
 
   bool parseViewportDescriptor(CSSPropertyID propId, bool important);
   bool parseFontFaceDescriptor(CSSPropertyID);
@@ -117,7 +117,7 @@ class CSSPropertyParser {
  private:
   // Inputs:
   CSSParserTokenRange m_range;
-  const CSSParserContext& m_context;
+  Persistent<const CSSParserContext> m_context;

[haraken, 2017/01/11 02:42:18]

This object is stack-allocated, so you can just use a raw pointer.

keishi@: Can we add a check to the clang plugin to detect Persistent handles in
stack-allocated objects?

[Bret, 2017/01/11 23:05:15]

It does not compile with a raw pointer. Clang gives me "[blink-gc] Raw pointer
field 'm_context' to a GC managed class"

[haraken, 2017/01/12 04:51:13]

Sorry, it should be Member<const CSSParserContext>.

[Bret, 2017/01/13 02:15:28]

Done.

   // Outputs:
   HeapVector<CSSProperty, 256>* m_parsedProperties;
 };