[turbofan] Refactor JSInliner to be a Reducer.

src/compiler/js-inlining.h

 // 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.
 
 #ifndef V8_COMPILER_JS_INLINING_H_
 #define V8_COMPILER_JS_INLINING_H_
 
 #include "src/compiler/js-graph.h"
+#include "src/compiler/graph-reducer.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 class JSCallFunctionAccessor;
 
-class JSInliner {
+class JSInliner FINAL : public Reducer {
  public:
   JSInliner(Zone* local_zone, CompilationInfo* info, JSGraph* jsgraph)
       : local_zone_(local_zone), info_(info), jsgraph_(jsgraph) {}
 
-  void Inline();
-  void TryInlineJSCall(Node* node);
+  Reduction Reduce(Node* node) OVERRIDE;
 
  private:
   friend class InlinerVisitor;
   Zone* local_zone_;
   CompilationInfo* info_;
   JSGraph* jsgraph_;
 
   Node* CreateArgumentsAdaptorFrameState(JSCallFunctionAccessor* call,
                                          Handle<JSFunction> jsfunction,
                                          Zone* temp_zone);
   void AddClosureToFrameState(Node* frame_state, Handle<JSFunction> jsfunction);
+  Reduction TryInlineJSCall(Node* node, Handle<JSFunction> jsfunction);
   static void UnifyReturn(Graph* graph);
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_JS_INLINING_H_