Switch BlinkGCPluginConsumer to use ranged for-loops.

tools/clang/blink_gc_plugin/BlinkGCPluginConsumer.h

 // Copyright 2015 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.
 
 #ifndef TOOLS_BLINK_GC_PLUGIN_BLINK_GC_PLUGIN_CONSUMER_H_
 #define TOOLS_BLINK_GC_PLUGIN_BLINK_GC_PLUGIN_CONSUMER_H_
 
 #include <string>
 
 #include "BlinkGCPluginOptions.h"
@@ skipping 78 matching lines @@
       clang::SourceLocation location,
       unsigned diag_id);
 
   void ReportClassMustLeftMostlyDeriveGC(RecordInfo* info);
   void ReportClassRequiresTraceMethod(RecordInfo* info);
   void ReportBaseRequiresTracing(RecordInfo* derived,
                                  clang::CXXMethodDecl* trace,
                                  clang::CXXRecordDecl* base);
   void ReportFieldsRequireTracing(RecordInfo* info,
                                   clang::CXXMethodDecl* trace);
-  void ReportClassContainsInvalidFields(RecordInfo* info,
-                                        CheckFieldsVisitor::Errors* errors);
+  void ReportClassContainsInvalidFields(
+      RecordInfo* info,
+      const CheckFieldsVisitor::Errors& errors);
   void ReportClassContainsGCRoots(RecordInfo* info,
-                                  CheckGCRootsVisitor::Errors* errors);
+                                  const CheckGCRootsVisitor::Errors& errors);
   void ReportFinalizerAccessesFinalizedFields(
       clang::CXXMethodDecl* dtor,
-      CheckFinalizerVisitor::Errors* fields);
+      const CheckFinalizerVisitor::Errors& errors);
   void ReportClassRequiresFinalization(RecordInfo* info);
   void ReportClassDoesNotRequireFinalization(RecordInfo* info);
   void ReportClassMustDeclareGCMixinTraceMethod(RecordInfo* info);
   void ReportOverriddenNonVirtualTrace(RecordInfo* info,
                                        clang::CXXMethodDecl* trace,
                                        clang::CXXMethodDecl* overridden);
   void ReportMissingTraceDispatchMethod(RecordInfo* info);
   void ReportMissingFinalizeDispatchMethod(RecordInfo* info);
   void ReportMissingDispatchMethod(RecordInfo* info, unsigned error);
   void ReportVirtualAndManualDispatch(RecordInfo* info,
@@ skipping 71 matching lines @@
 
   clang::CompilerInstance& instance_;
   clang::DiagnosticsEngine& diagnostic_;
   BlinkGCPluginOptions options_;
   RecordCache cache_;
   JsonWriter* json_;
 };
 
 
 #endif  // TOOLS_BLINK_GC_PLUGIN_BLINK_GC_PLUGIN_CONSUMER_H_