blink_gc_plugin: detect singletons with embedded ScriptWrappables.

tools/clang/blink_gc_plugin/RecordInfo.h

Index: tools/clang/blink_gc_plugin/RecordInfo.h
diff --git a/tools/clang/blink_gc_plugin/RecordInfo.h b/tools/clang/blink_gc_plugin/RecordInfo.h
index 220a6d3b3138f25625aac0c6a285079f11727058..f26647bc8b1c8a404ca4d945d06951d3d103ad4e 100644
--- a/tools/clang/blink_gc_plugin/RecordInfo.h
+++ b/tools/clang/blink_gc_plugin/RecordInfo.h
@@ -118,6 +118,16 @@ class RecordInfo {
 
   static clang::CXXRecordDecl* GetDependentTemplatedDecl(const clang::Type&);
 
+  // If |RecordInfo| represents blink::(CrossThread)Persistent<T>, return
+  // its type. |has_persistent_name| is set to |true| if the base type name
+  // is |Persistent| or |CrossThreadPersistent|.
+  const clang::Type* GetPersistentArgumentType(bool& has_persistent_name);
+
+  RecordCache* cache() const { return cache_; }
+
+  // Returns |true| if type is declared in "blink::"
+  bool IsInBlinkNamespace();
+
  private:
   RecordInfo(clang::CXXRecordDecl* record, RecordCache* cache);