Introduce subclass wrappers for STL containers that make them a lot easier

src/compiler/graph-reducer.cc

 // Copyright 2014 the V8 project 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 "src/compiler/graph-reducer.h"
 
 #include <functional>
 
 #include "src/compiler/graph-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 GraphReducer::GraphReducer(Graph* graph)
-    : graph_(graph), reducers_(Reducers::allocator_type(graph->zone())) {}
+    : graph_(graph), reducers_(graph->zone()) {}
 
 
 static bool NodeIdIsLessThan(const Node* node, NodeId id) {
   return node->id() < id;
 }
 
 
 void GraphReducer::ReduceNode(Node* node) {
-  Reducers::iterator skip = reducers_.end();
+  ZoneVector<Reducer*>::iterator skip = reducers_.end();
   static const unsigned kMaxAttempts = 16;
   bool reduce = true;
   for (unsigned attempts = 0; attempts <= kMaxAttempts; ++attempts) {
     if (!reduce) return;
     reduce = false;  // Assume we don't need to rerun any reducers.
     int before = graph_->NodeCount();
-    for (Reducers::iterator i = reducers_.begin(); i != reducers_.end(); ++i) {
+    for (ZoneVector<Reducer*>::iterator i = reducers_.begin();
+         i != reducers_.end(); ++i) {
       if (i == skip) continue;  // Skip this reducer.
       Reduction reduction = (*i)->Reduce(node);
       Node* replacement = reduction.replacement();
       if (replacement == NULL) {
         // No change from this reducer.
       } else if (replacement == node) {
         // {replacement == node} represents an in-place reduction.
         // Rerun all the reducers except the current one for this node,
         // as now there may be more opportunities for reduction.
         reduce = true;
@@ skipping 42 matching lines @@
   GraphReducerVisitor visitor(this);
   // Perform a post-order reduction of all nodes starting from the end.
   graph()->VisitNodeInputsFromEnd(&visitor);
 }
 
 
 // TODO(titzer): partial graph reductions.
 }
 }
 }  // namespace v8::internal::compiler