Add pause/resume for isolates in vmservice/observatory.

runtime/vm/isolate.h

 // 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.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/thread.h"
@@ skipping 308 matching lines @@
   Mutex* mutex() const { return mutex_; }
 
   Debugger* debugger() const { return debugger_; }
 
   void set_single_step(bool value) { single_step_ = value; }
   bool single_step() const { return single_step_; }
   static intptr_t single_step_offset() {
     return OFFSET_OF(Isolate, single_step_);
   }
 
+  // Requests that the debugger resume execution.
+  void Resume() {
+    resume_request_ = true;
+  }
+
+  // Returns whether the vm service has requested that the debugger
+  // resume execution.
+  bool GetAndClearResumeRequest() {
+    bool resume_request = resume_request_;
+    resume_request_ = false;
+    return resume_request;
+  }
+
   Random* random() { return &random_; }
 
   Simulator* simulator() const { return simulator_; }
   void set_simulator(Simulator* value) { simulator_ = value; }
 
   Dart_GcPrologueCallback gc_prologue_callback() const {
     return gc_prologue_callback_;
   }
 
   void set_gc_prologue_callback(Dart_GcPrologueCallback callback) {
@@ skipping 204 matching lines @@
   ObjectStore* object_store_;
   RawContext* top_context_;
   uword top_exit_frame_info_;
   void* init_callback_data_;
   Dart_EnvironmentCallback environment_callback_;
   Dart_LibraryTagHandler library_tag_handler_;
   ApiState* api_state_;
   StubCode* stub_code_;
   Debugger* debugger_;
   bool single_step_;
+  bool resume_request_;
   Random random_;
   Simulator* simulator_;
   LongJumpScope* long_jump_base_;
   TimerList timer_list_;
   intptr_t deopt_id_;
   Mutex* mutex_;  // protects stack_limit_ and saved_stack_limit_.
   uword stack_limit_;
   uword saved_stack_limit_;
   uword stack_overflow_flags_;
   int32_t stack_overflow_count_;
@@ skipping 157 matching lines @@
   char* script_url_;
   char* library_url_;
   char* class_name_;
   char* function_name_;
   char* exception_callback_name_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_