Track Hydrogen statistics on a per-Isolate basis

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 6be75816826a9184bd772737af466afd16c9181b..b3a056fa1b35d2f2c04b98d8a3e1f84f31080b05 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -61,6 +61,7 @@ class HBasicBlock: public ZoneObject {
   int block_id() const { return block_id_; }
   void set_block_id(int id) { block_id_ = id; }
   HGraph* graph() const { return graph_; }
+  Isolate* isolate() const;
   const ZoneList<HPhi*>* phis() const { return &phis_; }
   HInstruction* first() const { return first_; }
   HInstruction* last() const { return last_; }
@@ -870,7 +871,8 @@ class HGraphBuilder {
     return current_block()->last_environment();
   }
   Zone* zone() const { return info_->zone(); }
-  HGraph* graph() { return graph_; }
+  HGraph* graph() const { return graph_; }
+  Isolate* isolate() const { return graph_->isolate(); }
 
   HGraph* CreateGraph();
 
@@ -1534,16 +1536,20 @@ class HSideEffectMap BASE_EMBEDDED {
 
 class HStatistics: public Malloced {
  public:
+  HStatistics()
+      : timing_(5),
+        names_(5),
+        sizes_(5),
+        create_graph_(0),
+        optimize_graph_(0),
+        generate_code_(0),
+        total_size_(0),
+        full_code_gen_(0),
+        source_size_(0) { }
+
   void Initialize(CompilationInfo* info);
   void Print();
   void SaveTiming(const char* name, int64_t ticks, unsigned size);
-  static HStatistics* Instance() {
-    static SetOncePointer<HStatistics> instance;
-    if (!instance.is_set()) {
-      instance.set(new HStatistics());
-    }
-    return instance.get();
-  }
 
   void IncrementSubtotals(int64_t create_graph,
                           int64_t optimize_graph,
@@ -1554,17 +1560,6 @@ class HStatistics: public Malloced {
   }
 
  private:
-  HStatistics()
-      : timing_(5),
-        names_(5),
-        sizes_(5),
-        create_graph_(0),
-        optimize_graph_(0),
-        generate_code_(0),
-        total_size_(0),
-        full_code_gen_(0),
-        source_size_(0) { }
-
   List<int64_t> timing_;
   List<const char*> names_;
   List<unsigned> sizes_;
@@ -1589,10 +1584,10 @@ class HPhase BASE_EMBEDDED {
 
  private:
   void Init(Isolate* isolate,
-             const char* name,
-             HGraph* graph,
-             LChunk* chunk,
-             LAllocator* allocator);
+            const char* name,
+            HGraph* graph,
+            LChunk* chunk,
+            LAllocator* allocator);
 
   Isolate* isolate_;
   const char* name_;