BlinkGCPlugin: require GC mixin instances to declare local trace().

tools/clang/blink_gc_plugin/RecordInfo.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file provides a wrapper for CXXRecordDecl that accumulates GC related
 // information about a class. Accumulated information is memoized and the info
 // objects are stored in a RecordCache.
 
 #ifndef TOOLS_BLINK_GC_PLUGIN_RECORD_INFO_H_
 #define TOOLS_BLINK_GC_PLUGIN_RECORD_INFO_H_
@@ skipping 74 matching lines @@
   bool GetTemplateArgs(size_t count, TemplateArgs* output_args);
 
   bool IsHeapAllocatedCollection();
   bool IsGCDerived();
   bool IsGCAllocated();
   bool IsGCFinalized();
   bool IsGCMixin();
   bool IsStackAllocated();
   bool IsNonNewable();
   bool IsOnlyPlacementNewable();
+  bool IsGCMixinInstance();
   clang::CXXMethodDecl* DeclaresNewOperator();
 
   bool RequiresTraceMethod();
   bool NeedsFinalization();
+  bool DeclaresGCMixinMethods();
+  bool DeclaresLocalTraceMethod();
   TracingStatus NeedsTracing(Edge::NeedsTracingOption);
   clang::CXXMethodDecl* InheritsNonVirtualTrace();
   bool IsConsideredAbstract();
 
   static clang::CXXRecordDecl* GetDependentTemplatedDecl(const clang::Type&);
 
  private:
   RecordInfo(clang::CXXRecordDecl* record, RecordCache* cache);
 
   void walkBases();
@@ skipping 10 matching lines @@
   const std::string name_;
   TracingStatus fields_need_tracing_;
   Bases* bases_;
   Fields* fields_;
 
   enum CachedBool { kFalse = 0, kTrue = 1, kNotComputed = 2 };
   CachedBool is_stack_allocated_;
   CachedBool is_non_newable_;
   CachedBool is_only_placement_newable_;
   CachedBool does_need_finalization_;
+  CachedBool has_gc_mixin_methods_;
+  CachedBool is_declaring_local_trace_;
 
   bool determined_trace_methods_;
   clang::CXXMethodDecl* trace_method_;
   clang::CXXMethodDecl* trace_dispatch_method_;
   clang::CXXMethodDecl* finalize_dispatch_method_;
 
   bool is_gc_derived_;
 
   std::vector<std::string> gc_base_names_;
 
@@ skipping 31 matching lines @@
       }
     }
   }
 
  private:
   typedef std::map<clang::CXXRecordDecl*, RecordInfo> Cache;
   Cache cache_;
 };
 
 #endif  // TOOLS_BLINK_GC_PLUGIN_RECORD_INFO_H_