[DevTools] Inherit WI.Target from Protocol.Target.

third_party/WebKit/Source/devtools/front_end/sdk/HeapProfilerModel.js

 /**
  * @constructor
  * @extends {WebInspector.SDKModel}
  * @param {!WebInspector.Target} target
  */
 WebInspector.HeapProfilerModel = function(target)
 {
     WebInspector.SDKModel.call(this, WebInspector.HeapProfilerModel, target);
     target.registerHeapProfilerDispatcher(new WebInspector.HeapProfilerDispatcher(this));
     this._enabled = false;
@@ skipping 24 matching lines @@
         var defaultSamplingIntervalInBytes = 16384;
         this._heapProfilerAgent.startSampling(defaultSamplingIntervalInBytes);
     },
 
     /**
      * @return {!Promise.<?ProfilerAgent.Profile>}
      */
     stopSampling: function()
     {
         this._isRecording = false;
-        var currentProfile = null;
-        return this._heapProfilerAgent.stopSampling((error, profile) => { currentProfile = !error ? profile : null; })
-            .then(() => currentProfile);
+        return this._heapProfilerAgent.stopSampling((error, profile) => error ? null : profile);
     },
 
     /**
      * @param {!Array.<number>} samples
      */
     heapStatsUpdate: function(samples)
     {
         this.dispatchEventToListeners(WebInspector.HeapProfilerModel.Events.HeapStatsUpdate, samples);
     },
 
@@ skipping 83 matching lines @@
     },
 
     /**
      * @override
      */
     resetProfiles: function()
     {
         this._heapProfilerModel.resetProfiles();
     }
 };