PATCH (not to be comitted): Support for printing instruction statistics

runtime/vm/flow_graph_compiler.h

Index: runtime/vm/flow_graph_compiler.h
diff --git a/runtime/vm/flow_graph_compiler.h b/runtime/vm/flow_graph_compiler.h
index afdb4cb0a7bff56de4f7de68e5c6c1d5debc03e6..0d0b1f0e453fc0e674fc97611ed7e3856be95faa 100644
--- a/runtime/vm/flow_graph_compiler.h
+++ b/runtime/vm/flow_graph_compiler.h
@@ -10,6 +10,7 @@
 #include "vm/code_descriptors.h"
 #include "vm/code_generator.h"
 #include "vm/intermediate_language.h"
+#include "vm/code_statistics.h"
 
 namespace dart {
 
@@ -268,7 +269,8 @@ class FlowGraphCompiler : public ValueObject {
                     bool is_optimizing,
                     const GrowableArray<const Function*>& inline_id_to_function,
                     const GrowableArray<TokenPosition>& inline_id_to_token_pos,
-                    const GrowableArray<intptr_t>& caller_inline_id);
+                    const GrowableArray<intptr_t>& caller_inline_id,
+                    CodeStatistics* stats = NULL);
 
   ~FlowGraphCompiler();
 
@@ -312,6 +314,22 @@ class FlowGraphCompiler : public ValueObject {
     return &parallel_move_resolver_;
   }
 
+  void StatsBegin(Instruction* instr) {
+    if (stats_ != NULL) stats_->Begin(instr);
+  }
+
+  void StatsEnd(Instruction* instr) {
+    if (stats_ != NULL) stats_->End(instr);
+  }
+
+  void SpecialStatsBegin(intptr_t tag) {
+    if (stats_ != NULL) stats_->SpecialBegin(tag);
+  }
+
+  void SpecialStatsEnd(intptr_t tag) {
+    if (stats_ != NULL) stats_->SpecialEnd(tag);
+  }
+
   // Constructor is lighweight, major initialization work should occur here.
   // This makes it easier to measure time spent in the compiler.
   void InitCompiler();
@@ -792,6 +810,7 @@ class FlowGraphCompiler : public ValueObject {
   const GrowableArray<const Function*>& inline_id_to_function_;
   const GrowableArray<TokenPosition>& inline_id_to_token_pos_;
   const GrowableArray<intptr_t>& caller_inline_id_;
+  CodeStatistics* stats_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };