Remove duplicated LChunk code.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index ac19db71fb6e7fb0f3b55edfbe93a9bffad8cabf..74d6a7bac6bbd33049639a5a183f1579329106e6 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -48,7 +48,7 @@ class HGraph;
 class HLoopInformation;
 class HTracer;
 class LAllocator;
-class LChunk;
+class LChunkBase;
 class LiveRange;
 
 
@@ -1336,7 +1336,7 @@ class HPhase BASE_EMBEDDED {
   HPhase(const char* name, HGraph* graph) {
     Begin(name, graph, NULL, NULL);
   }
-  HPhase(const char* name, LChunk* chunk) {
+  HPhase(const char* name, LChunkBase* chunk) {
     Begin(name, NULL, chunk, NULL);
   }
   HPhase(const char* name, LAllocator* allocator) {
@@ -1350,14 +1350,14 @@ class HPhase BASE_EMBEDDED {
  private:
   void Begin(const char* name,
              HGraph* graph,
-             LChunk* chunk,
+             LChunkBase* chunk,
              LAllocator* allocator);
   void End() const;
 
   int64_t start_;
   const char* name_;
   HGraph* graph_;
-  LChunk* chunk_;
+  LChunkBase* chunk_;
   LAllocator* allocator_;
   unsigned start_allocation_size_;
 };
@@ -1367,7 +1367,7 @@ class HTracer: public Malloced {
  public:
   void TraceCompilation(FunctionLiteral* function);
   void TraceHydrogen(const char* name, HGraph* graph);
-  void TraceLithium(const char* name, LChunk* chunk);
+  void TraceLithium(const char* name, LChunkBase* chunk);
   void TraceLiveRanges(const char* name, LAllocator* allocator);
 
   static HTracer* Instance() {
@@ -1408,7 +1408,7 @@ class HTracer: public Malloced {
   }
 
   void TraceLiveRange(LiveRange* range, const char* type, Zone* zone);
-  void Trace(const char* name, HGraph* graph, LChunk* chunk);
+  void Trace(const char* name, HGraph* graph, LChunkBase* chunk);
   void FlushToFile();
 
   void PrintEmptyProperty(const char* name) {