tools/gn: Change auto to not deduce raw pointers.

tools/gn/scope.cc

 // Copyright (c) 2013 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 "tools/gn/scope.h"
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/template.h"
@@ skipping 51 matching lines @@
       mode_flags_(0),
       item_collector_(nullptr) {
 }
 
 Scope::~Scope() {
 }
 
 const Value* Scope::GetValue(const base::StringPiece& ident,
                              bool counts_as_used) {
   // First check for programmatically-provided values.
-  for (const auto& provider : programmatic_providers_) {
+  for (auto* provider : programmatic_providers_) {
     const Value* v = provider->GetProgrammaticValue(ident);
     if (v)
       return v;
   }
 
   RecordMap::iterator found = values_.find(ident);
   if (found != values_.end()) {
     if (counts_as_used)
       found->second.used = true;
     return &found->second.value;
@@ skipping 424 matching lines @@
 }
 
 void Scope::AddProvider(ProgrammaticProvider* p) {
   programmatic_providers_.insert(p);
 }
 
 void Scope::RemoveProvider(ProgrammaticProvider* p) {
   DCHECK(programmatic_providers_.find(p) != programmatic_providers_.end());
   programmatic_providers_.erase(p);
 }