BlinkGCPlugin: Fix detection of trace dispatching after inlined tracing.

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 297 matching lines @@
   bool dispatched_to_receiver() { return dispatched_to_receiver_; }
 
   bool VisitMemberExpr(MemberExpr* member) {
     if (CXXMethodDecl* fn = dyn_cast<CXXMethodDecl>(member->getMemberDecl())) {
       if (fn->getParent() == receiver_->record())
         dispatched_to_receiver_ = true;
     }
     return true;
   }
 
+  bool VisitUnresolvedMemberExpr(UnresolvedMemberExpr* member) {
+    for (Decl* decl : member->decls()) {
+      if (CXXMethodDecl* method = dyn_cast<CXXMethodDecl>(decl)) {
+        if (method->getParent() == receiver_->record() &&
+            Config::GetTraceMethodType(method) ==
+            Config::TRACE_AFTER_DISPATCH_METHOD) {
+          dispatched_to_receiver_ = true;
+          return true;
+        }
+      }
+    }
+    return true;
+  }
+
  private:
   RecordInfo* receiver_;
   bool dispatched_to_receiver_;
 };
 
 // This visitor checks a tracing method by traversing its body.
 // - A member field is considered traced if it is referenced in the body.
 // - A base is traced if a base-qualified call to a trace method is found.
 class CheckTraceVisitor : public RecursiveASTVisitor<CheckTraceVisitor> {
  public:
@@ skipping 1072 matching lines @@
       }
       return;
     }
 
     CheckTraceOrDispatchMethod(parent, method);
   }
 
   // Determine what type of tracing method this is (dispatch or trace).
   void CheckTraceOrDispatchMethod(RecordInfo* parent, CXXMethodDecl* method) {
     Config::TraceMethodType trace_type = Config::GetTraceMethodType(method);
-    if (trace_type != Config::TRACE_METHOD ||
+    if (trace_type == Config::TRACE_AFTER_DISPATCH_METHOD ||
+        trace_type == Config::TRACE_AFTER_DISPATCH_IMPL_METHOD ||
         !parent->GetTraceDispatchMethod()) {
       CheckTraceMethod(parent, method, trace_type);
     }
     // Dispatch methods are checked when we identify subclasses.
   }
 
   // Check an actual trace method.
   void CheckTraceMethod(RecordInfo* parent,
                         CXXMethodDecl* trace,
                         Config::TraceMethodType trace_type) {
@@ skipping 611 matching lines @@
 
  private:
   BlinkGCPluginOptions options_;
 };
 
 }  // namespace
 
 static FrontendPluginRegistry::Add<BlinkGCPluginAction> X(
     "blink-gc-plugin",
     "Check Blink GC invariants");