Update from https://crrev.com/317530

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 452 matching lines @@
 
   bool CheckTraceBaseCall(CallExpr* call) {
     MemberExpr* callee = dyn_cast<MemberExpr>(call->getCallee());
     if (!callee)
       return false;
 
     FunctionDecl* fn = dyn_cast<FunctionDecl>(callee->getMemberDecl());
     if (!fn || !Config::IsTraceMethod(fn, nullptr))
       return false;
 
-    // Currently, a manually dispatched class cannot have mixin bases (having
-    // one would add a vtable which we explicitly check against). This means
-    // that we can only make calls to a trace method of the same name. Revisit
-    // this if our mixin/vtable assumption changes.
-    if (fn->getName() != trace_->getName())
-      return false;
+    if (trace_->getName() == kTraceImplName) {
+      if (fn->getName() != kTraceName)
+        return false;
+    } else {
+      // Currently, a manually dispatched class cannot have mixin bases (having
+      // one would add a vtable which we explicitly check against). This means
+      // that we can only make calls to a trace method of the same name. Revisit
+      // this if our mixin/vtable assumption changes.
+      if (fn->getName() != trace_->getName())
+        return false;
+    }
 
     CXXRecordDecl* decl = 0;
     if (callee && callee->hasQualifier()) {
       if (const Type* type = callee->getQualifier()->getAsType())
         decl = type->getAsCXXRecordDecl();
     }
     if (!decl)
       return false;
 
     RecordInfo::Bases::iterator it = info_->GetBases().find(decl);
@@ skipping 1445 matching lines @@
 
  private:
   BlinkGCPluginOptions options_;
 };
 
 }  // namespace
 
 static FrontendPluginRegistry::Add<BlinkGCPluginAction> X(
     "blink-gc-plugin",
     "Check Blink GC invariants");