DevTools: introduce multitarget model listeners

Source/devtools/front_end/components/ExecutionContextSelector.js

Index: Source/devtools/front_end/components/ExecutionContextSelector.js
diff --git a/Source/devtools/front_end/components/ExecutionContextSelector.js b/Source/devtools/front_end/components/ExecutionContextSelector.js
index 1a85cca8dc059a506f8955b483bc0fceeb41a33f..2a3a5b2ef558df4384609da7eeca61841f1f4a2c 100644
--- a/Source/devtools/front_end/components/ExecutionContextSelector.js
+++ b/Source/devtools/front_end/components/ExecutionContextSelector.js
@@ -11,6 +11,9 @@ WebInspector.ExecutionContextSelector = function()
     WebInspector.targetManager.observeTargets(this);
     WebInspector.context.addFlavorChangeListener(WebInspector.ExecutionContext, this._executionContextChanged, this);
     WebInspector.context.addFlavorChangeListener(WebInspector.Target, this._targetChanged, this);
+
+    WebInspector.targetManager.addModelListener(WebInspector.RuntimeModel, WebInspector.RuntimeModel.Events.ExecutionContextCreated, this._onExecutionContextCreated, this);
+    WebInspector.targetManager.addModelListener(WebInspector.RuntimeModel, WebInspector.RuntimeModel.Events.ExecutionContextDestroyed, this._onExecutionContextDestroyed, this);
 }
 
 WebInspector.ExecutionContextSelector.prototype = {
@@ -22,9 +25,6 @@ WebInspector.ExecutionContextSelector.prototype = {
     {
         if (!WebInspector.context.flavor(WebInspector.Target))
             WebInspector.context.setFlavor(WebInspector.Target, target);
-
-        target.runtimeModel.addEventListener(WebInspector.RuntimeModel.Events.ExecutionContextCreated, this._onExecutionContextCreated, this);
-        target.runtimeModel.addEventListener(WebInspector.RuntimeModel.Events.ExecutionContextDestroyed, this._onExecutionContextDestroyed, this);
     },
 
     /**
@@ -32,8 +32,6 @@ WebInspector.ExecutionContextSelector.prototype = {
      */
     targetRemoved: function(target)
     {
-        target.runtimeModel.removeEventListener(WebInspector.RuntimeModel.Events.ExecutionContextCreated, this._onExecutionContextCreated, this);
-        target.runtimeModel.removeEventListener(WebInspector.RuntimeModel.Events.ExecutionContextDestroyed, this._onExecutionContextDestroyed, this);
         var currentExecutionContext = WebInspector.context.flavor(WebInspector.ExecutionContext);
         if (currentExecutionContext && currentExecutionContext.target() === target)
             this._currentExecutionContextGone();