Support profiler code transition tags

runtime/vm/profiler_service.h

Index: runtime/vm/profiler_service.h
diff --git a/runtime/vm/profiler_service.h b/runtime/vm/profiler_service.h
index 590b84e8f17474eb6de29ec9bb789ce2b866d89a..894b1fde9e71a91fe088249083b7532d97f6f9a7 100644
--- a/runtime/vm/profiler_service.h
+++ b/runtime/vm/profiler_service.h
@@ -300,7 +300,7 @@ class Profile : public ValueObject {
   explicit Profile(Isolate* isolate);
 
   // Build a filtered model using |filter| with the specified |tag_order|.
-  void Build(SampleFilter* filter, TagOrder tag_order);
+  void Build(SampleFilter* filter, TagOrder tag_order, intptr_t extra_tags = 0);
 
   // After building:
   int64_t min_time() const { return min_time_; }
@@ -371,8 +371,13 @@ class ProfileTrieWalker : public ValueObject {
 
 class ProfilerService : public AllStatic {
  public:
+  enum {
+    kCodeTransitionTagsBit = (1 << 0),
+  };
+
   static void PrintJSON(JSONStream* stream,
-                        Profile::TagOrder tag_order);
+                        Profile::TagOrder tag_order,
+                        intptr_t extra_tags);
 
   static void PrintAllocationJSON(JSONStream* stream,
                                   Profile::TagOrder tag_order,
@@ -384,6 +389,7 @@ class ProfilerService : public AllStatic {
   static void PrintJSONImpl(Isolate* isolate,
                             JSONStream* stream,
                             Profile::TagOrder tag_order,
+                            intptr_t extra_tags,
                             SampleFilter* filter);
 };