Switch profiler from isolates to threads

runtime/vm/thread_interrupter_linux.cc

Index: runtime/vm/thread_interrupter_linux.cc
diff --git a/runtime/vm/thread_interrupter_linux.cc b/runtime/vm/thread_interrupter_linux.cc
index d7b9b8532abf2e3fd05d76603f5ff89e81dedf69..a09f1b782acec3f62e82a770f73246f519cd110a 100644
--- a/runtime/vm/thread_interrupter_linux.cc
+++ b/runtime/vm/thread_interrupter_linux.cc
@@ -5,6 +5,8 @@
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
+#include <errno.h>  // NOLINT
+
 #include "vm/flags.h"
 #include "vm/os.h"
 #include "vm/signal_handler.h"
@@ -27,8 +29,7 @@ class ThreadInterrupterLinux : public AllStatic {
       return;
     }
     ThreadInterruptCallback callback = NULL;
-    void* callback_data = NULL;
-    if (!thread->IsThreadInterrupterEnabled(&callback, &callback_data)) {
+    if (!thread->GetThreadInterruptCallback(&callback)) {
       return;
     }
     // Extract thread state.
@@ -41,7 +42,7 @@ class ThreadInterrupterLinux : public AllStatic {
     its.csp = SignalHandler::GetCStackPointer(mcontext);
     its.dsp = SignalHandler::GetDartStackPointer(mcontext);
     its.lr = SignalHandler::GetLinkRegister(mcontext);
-    callback(its, callback_data);
+    callback(thread, its);
   }
 };
 
@@ -52,7 +53,7 @@ void ThreadInterrupter::InterruptThread(Thread* thread) {
               reinterpret_cast<void*>(thread->id()));
   }
   int result = pthread_kill(thread->id(), SIGPROF);
-  ASSERT(result == 0);
+  ASSERT((result == 0) || (result == ESRCH));
 }