Add fine grained command line and service protocol control over timeline streams recording

runtime/vm/timeline.h

Index: runtime/vm/timeline.h
diff --git a/runtime/vm/timeline.h b/runtime/vm/timeline.h
index cf77396be4b8d5e8b4f013acbaff543938edd714..f44fb53a0c2537b819b47b983999c064b1f00846 100644
--- a/runtime/vm/timeline.h
+++ b/runtime/vm/timeline.h
@@ -46,7 +46,7 @@ class Timeline : public AllStatic {
   // Access the global recorder. Not thread safe.
   static TimelineEventRecorder* recorder();
 
-  static bool EnableStreamByDefault(const char* stream_name);
+  static void SetupIsolateStreams(Isolate* isolate);
 
   static TimelineStream* GetVMStream();
 
@@ -57,6 +57,9 @@ class Timeline : public AllStatic {
 
   static void Clear();
 
+  // Print information about streams to JSON.
+  static void PrintFlagsToJSON(JSONStream* json);
+
 #define ISOLATE_TIMELINE_STREAM_FLAGS(name, not_used)                          \
   static const bool* Stream##name##EnabledFlag() {                             \
     return &stream_##name##_enabled_;                                          \
@@ -66,11 +69,13 @@ class Timeline : public AllStatic {
   }
   ISOLATE_TIMELINE_STREAM_LIST(ISOLATE_TIMELINE_STREAM_FLAGS)
 #undef ISOLATE_TIMELINE_STREAM_FLAGS
+  static void SetVMStreamEnabled(bool enabled);
 
  private:
   static TimelineEventRecorder* recorder_;
   static TimelineStream vm_stream_;
   static TimelineStream vm_api_stream_;
+  static MallocGrowableArray<char*>* enabled_streams_;
 
 #define ISOLATE_TIMELINE_STREAM_DECLARE_FLAG(name, not_used)                   \
   static bool stream_##name##_enabled_;
@@ -618,7 +623,7 @@ class TimelineEventRecorder {
   // Interface method(s) which must be implemented.
   virtual void PrintJSON(JSONStream* js, TimelineEventFilter* filter) = 0;
   virtual void PrintTraceEvent(JSONStream* js, TimelineEventFilter* filter) = 0;
-
+  virtual const char* name() const = 0;
   int64_t GetNextAsyncId();
 
   void FinishBlock(TimelineEventBlock* block);
@@ -662,6 +667,9 @@ class TimelineEventRingRecorder : public TimelineEventRecorder {
 
   void PrintJSON(JSONStream* js, TimelineEventFilter* filter);
   void PrintTraceEvent(JSONStream* js, TimelineEventFilter* filter);
+  const char* name() const {
+    return "ring";
+  }
 
  protected:
   TimelineEvent* StartEvent();
@@ -693,6 +701,10 @@ class TimelineEventStreamingRecorder : public TimelineEventRecorder {
   // reference to |event| as it may be freed as soon as this function returns.
   virtual void StreamEvent(TimelineEvent* event) = 0;
 
+  const char* name() const {
+    return "streaming";
+  }
+
  protected:
   TimelineEventBlock* GetNewBlockLocked() {
     return NULL;
@@ -717,6 +729,10 @@ class TimelineEventEndlessRecorder : public TimelineEventRecorder {
   void PrintJSON(JSONStream* js, TimelineEventFilter* filter);
   void PrintTraceEvent(JSONStream* js, TimelineEventFilter* filter);
 
+  const char* name() const {
+    return "endless";
+  }
+
  protected:
   TimelineEvent* StartEvent();
   void CompleteEvent(TimelineEvent* event);