Blink GC plugin: require that GC derived classes do not override their new(size_t) operator.

tools/clang/blink_gc_plugin/RecordInfo.cpp

 // 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.
 
 #include "Config.h"
 #include "RecordInfo.h"
 
 using namespace clang;
 using std::string;
 
@@ skipping 212 matching lines @@
         } else if (it->getNumParams() == 2) {
           placement = !it->isDeleted();
         }
       }
     }
     is_only_placement_newable_ = (placement && new_deleted) ? kTrue : kFalse;
   }
   return is_only_placement_newable_;
 }
 
+CXXMethodDecl* RecordInfo::DeclaresNewOperator() {
+  for (CXXRecordDecl::method_iterator it = record_->method_begin();
+       it != record_->method_end();
+       ++it) {
+    if (it->getNameAsString() == kNewOperatorName && it->getNumParams() == 1)
+      return *it;
+  }
+  return 0;
+}
+
 // An object requires a tracing method if it has any fields that need tracing.
 bool RecordInfo::RequiresTraceMethod() {
   if (IsStackAllocated())
     return false;
   GetFields();
   return fields_need_tracing_.IsNeeded();
 }
 
 // Get the actual tracing method (ie, can be traceAfterDispatch if there is a
 // dispatch method).
@@ skipping 263 matching lines @@
         edge->members().push_back(member);
       }
       // TODO: Handle the case where we fail to create an edge (eg, if the
       // argument is a primitive type or just not fully known yet).
     }
     return edge;
   }
 
   return new Value(info);
 }