DevTools: release objects generated for REPL preview

Bug: none
Change-Id: Ic24e0f08fa6d55461d7bdd50d6164b00e47ab950
Reviewed-on: https://chromium-review.googlesource.com/1200402
Commit-Queue: Erik Luo <luoe@chromium.org>
Reviewed-by: Joel Einbinder <einbinder@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589860}

third_party/blink/renderer/devtools/front_end/console/ConsolePinPane.js

@@ -107,8 +107,10 @@ Console.ConsolePin = class extends Common.Object {
     nameElement.title = expression;
     this._pinElement[Console.ConsolePin._PinSymbol] = this;
 
-    /** @type {?SDK.RemoteObject} */
-    this._resultObject = null;
+    /** @type {?SDK.RuntimeModel.EvaluationResult} */
+    this._lastResult = null;
+    /** @type {?SDK.ExecutionContext} */
+    this._lastExecutionContext = null;
     /** @type {?UI.TextEditor} */
     this._editor = null;
     this._committedExpression = expression;
@@ -165,8 +167,8 @@ Console.ConsolePin = class extends Common.Object {
    * @param {!UI.ContextMenu} contextMenu
    */
   appendToContextMenu(contextMenu) {
-    if (this._resultObject)
-      contextMenu.appendApplicableItems(this._resultObject);
+    if (this._lastResult && this._lastResult.object)
+      contextMenu.appendApplicableItems(this._lastResult.object);
   }
 
   /**
@@ -179,9 +181,12 @@ Console.ConsolePin = class extends Common.Object {
     const isEditing = this._pinElement.hasFocus();
     const throwOnSideEffect = isEditing && text !== this._committedExpression;
     const timeout = throwOnSideEffect ? 250 : undefined;
+    this._lastExecutionContext = UI.context.flavor(SDK.ExecutionContext);
     const {preview, result} = await ObjectUI.JavaScriptREPL.evaluateAndBuildPreview(
         text, throwOnSideEffect, timeout, !isEditing /* allowErrors */);
-    this._resultObject = result ? (result.object || null) : null;
+    if (this._lastResult)
+      this._lastExecutionContext.runtimeModel.releaseEvaluationResult(this._lastResult);
+    this._lastResult = result || null;
     const previewText = preview.deepTextContent();
     if (!previewText || previewText !== this._pinPreview.deepTextContent()) {
       this._pinPreview.removeChildren();

third_party/blink/renderer/devtools/front_end/console/ConsolePrompt.js

@@ -96,6 +96,7 @@ Console.ConsolePrompt = class extends UI.Widget {
    */
   async _requestPreview() {
     const text = this._editor.textWithCurrentSuggestion().trim();
+    const executionContext = UI.context.flavor(SDK.ExecutionContext);
     const {preview, result} =
         await ObjectUI.JavaScriptREPL.evaluateAndBuildPreview(text, true /* throwOnSideEffect */, 500);
     this._innerPreviewElement.removeChildren();
@@ -108,6 +109,8 @@ Console.ConsolePrompt = class extends UI.Widget {
       this._highlightingNode = false;
       SDK.OverlayModel.hideDOMNodeHighlight();
     }
+    if (result)
+      executionContext.runtimeModel.releaseEvaluationResult(result);
   }
 
   /**

third_party/blink/renderer/devtools/front_end/sdk/RuntimeModel.js

@@ -209,6 +209,19 @@ SDK.RuntimeModel = class extends SDK.SDKModel {
     this._agent.releaseObjectGroup(objectGroupName);
   }
 
+  /**
+   * @param {!SDK.RuntimeModel.EvaluationResult} result
+   */
+  releaseEvaluationResult(result) {
+    if (result.object)
+      result.object.release();
+    if (result.exceptionDetails && result.exceptionDetails.exception) {
+      const exception = result.exceptionDetails.exception;
+      const exceptionObject = this.createRemoteObject({type: exception.type, objectId: exception.objectId});
+      exceptionObject.release();
+    }
+  }
+
   runIfWaitingForDebugger() {
     this._agent.runIfWaitingForDebugger();
   }