DevTools: migrate from external Maps to symbols in the bindings objects.

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

Index: third_party/WebKit/Source/devtools/front_end/sdk/Script.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/Script.js b/third_party/WebKit/Source/devtools/front_end/sdk/Script.js
index e71f869dc73481285b03ae277d61f0ce2736bee3..6ec78f518b2d8c85fdee2edbe2767e710edd6ac4 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/Script.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/Script.js
@@ -27,7 +27,7 @@
  * @implements {Common.ContentProvider}
  * @unrestricted
  */
-SDK.Script = class extends SDK.SDKObject {
+SDK.Script = class {
   /**
    * @param {!SDK.DebuggerModel} debuggerModel
    * @param {string} scriptId
@@ -57,7 +57,6 @@ SDK.Script = class extends SDK.SDKObject {
       isLiveEdit,
       sourceMapURL,
       hasSourceURL) {
-    super(debuggerModel.target());
     this.debuggerModel = debuggerModel;
     this.scriptId = scriptId;
     this.sourceURL = sourceURL;
@@ -65,6 +64,7 @@ SDK.Script = class extends SDK.SDKObject {
     this.columnOffset = startColumn;
     this.endLine = endLine;
     this.endColumn = endColumn;
+
     this._executionContextId = executionContextId;
     this.hash = hash;
     this._isContentScript = isContentScript;
@@ -122,6 +122,13 @@ SDK.Script = class extends SDK.SDKObject {
   }
 
   /**
+   * @return {!SDK.Target}
+   */
+  target() {
+    return this.debuggerModel.target();
+  }
+
+  /**
    * @return {boolean}
    */
   isContentScript() {