Revert "Switch profiler from isolates to threads"

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 6e668c84ffb555a4adbea9a2016dcf1beaba48fd..8ee0c5dc52f7611ff02fa23ed1bd11b4e67077d1 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -1464,21 +1464,25 @@ DART_EXPORT void Dart_EnterIsolate(Dart_Isolate isolate) {
 }
 
 
-DART_EXPORT void Dart_ThreadDisableProfiling() {
-  Thread* T = Thread::Current();
-  if (T == NULL) {
+DART_EXPORT void Dart_IsolateBlocked() {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  IsolateProfilerData* profiler_data = isolate->profiler_data();
+  if (profiler_data == NULL) {
     return;
   }
-  T->DisableThreadInterrupts();
+  profiler_data->Block();
 }
 
 
-DART_EXPORT void Dart_ThreadEnableProfiling() {
-  Thread* T = Thread::Current();
-  if (T == NULL) {
+DART_EXPORT void Dart_IsolateUnblocked() {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  IsolateProfilerData* profiler_data = isolate->profiler_data();
+  if (profiler_data == NULL) {
     return;
   }
-  T->EnableThreadInterrupts();
+  profiler_data->Unblock();
 }