Add necessary support functions so that embedders can implemented pause on start and exit

runtime/vm/service.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/service.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/globals.h"
 
@@ skipping 2940 matching lines @@
 
 static const MethodParameter* resume_params[] = {
   RUNNABLE_ISOLATE_PARAMETER,
   NULL,
 };
 
 
 static bool Resume(Thread* thread, JSONStream* js) {
   const char* step_param = js->LookupParam("step");
   Isolate* isolate = thread->isolate();
-  if (isolate->message_handler()->paused_on_start()) {
+  if (isolate->message_handler()->is_paused_on_start()) {
     // If the user is issuing a 'Over' or an 'Out' step, that is the
     // same as a regular resume request.
     if ((step_param != NULL) && (strcmp(step_param, "Into") == 0)) {
       isolate->debugger()->EnterSingleStepMode();
     }
-    isolate->message_handler()->set_pause_on_start(false);
-    isolate->set_last_resume_timestamp();
+    isolate->message_handler()->set_should_pause_on_start(false);
+    isolate->SetResumeRequest();
     if (Service::debug_stream.enabled()) {
       ServiceEvent event(isolate, ServiceEvent::kResume);
       Service::HandleEvent(&event);
     }
     PrintSuccess(js);
     return true;
   }
-  if (isolate->message_handler()->paused_on_exit()) {
-    isolate->message_handler()->set_pause_on_exit(false);
+  if (isolate->message_handler()->is_paused_on_exit()) {
+    isolate->message_handler()->set_should_pause_on_exit(false);
+    isolate->SetResumeRequest();
     // We don't send a resume event because we will be exiting.
     PrintSuccess(js);
     return true;
   }
   if (isolate->debugger()->PauseEvent() != NULL) {
     if (step_param != NULL) {
       if (strcmp(step_param, "Into") == 0) {
         isolate->debugger()->SetSingleStep();
       } else if (strcmp(step_param, "Over") == 0) {
         isolate->debugger()->SetStepOver();
       } else if (strcmp(step_param, "Out") == 0) {
         isolate->debugger()->SetStepOut();
       } else {
         PrintInvalidParamError(js, "step");
         return true;
       }
     }
-    isolate->Resume();
+    isolate->SetResumeRequest();
     PrintSuccess(js);
     return true;
   }
 
   js->PrintError(kVMMustBePaused, NULL);
   return true;
 }
 
 
 static const MethodParameter* pause_params[] = {
@@ skipping 946 matching lines @@
     const ServiceMethodDescriptor& method = service_methods_[i];
     if (strcmp(method_name, method.name) == 0) {
       return &method;
     }
   }
   return NULL;
 }
 
 
 }  // namespace dart