Blink GC plugin: TODO/OWNERS update.

tools/clang/blink_gc_plugin/BlinkGCPlugin.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.
 
 // This clang plugin checks various invariants of the Blink garbage
 // collection infrastructure.
 //
 // Errors are described at:
 // http://www.chromium.org/developers/blink-gc-plugin-errors
 
@@ skipping 939 matching lines @@
 
     if (CXXMethodDecl* trace = info->GetTraceMethod()) {
       if (trace->isPure())
         ReportClassDeclaresPureVirtualTrace(info, trace);
     } else if (info->RequiresTraceMethod()) {
       ReportClassRequiresTraceMethod(info);
     }
 
     // Check polymorphic classes that are GC-derived or have a trace method.
     if (info->record()->hasDefinition() && info->record()->isPolymorphic()) {
+      // TODO: Check classes that inherit a trace method.
       CXXMethodDecl* trace = info->GetTraceMethod();
       if (trace || info->IsGCDerived())
         CheckPolymorphicClass(info, trace);
     }
 
     {
       CheckFieldsVisitor visitor(options_);
       if (visitor.ContainsInvalidFields(info))
         ReportClassContainsInvalidFields(info, &visitor.invalid_fields());
     }
@@ skipping 904 matching lines @@
 
  private:
   BlinkGCPluginOptions options_;
 };
 
 }  // namespace
 
 static FrontendPluginRegistry::Add<BlinkGCPluginAction> X(
     "blink-gc-plugin",
     "Check Blink GC invariants");