debug: add context menu copy action to repl

fixes #3974

src/vs/workbench/parts/debug/browser/replViewer.ts

@@ -460,6 +460,7 @@ export class ReplExpressionsActionProvider implements renderer.IActionProvider {
 			actions.push(this.instantiationService.createInstance(debugactions.AddToWatchExpressionsAction, debugactions.AddToWatchExpressionsAction.ID, debugactions.AddToWatchExpressionsAction.LABEL, element));
 			actions.push(new actionbar.Separator());
 		}
+		actions.push(new debugactions.CopyAction(debugactions.CopyAction.ID, debugactions.CopyAction.LABEL));
 		actions.push(this.instantiationService.createInstance(debugactions.ClearReplAction, debugactions.ClearReplAction.ID, debugactions.ClearReplAction.LABEL));
 
 		return TPromise.as(actions);

src/vs/workbench/parts/debug/electron-browser/debugActions.ts

@@ -705,6 +705,16 @@ export class ClearReplAction extends AbstractDebugAction {
 	}
 }
 
+export class CopyAction extends actions.Action {
+	static ID = 'workbench.debug.action.copy';
+	static LABEL = nls.localize('copy', "Copy");
+
+	public run(): TPromise<any> {
+		clipboard.writeText(window.getSelection().toString());
+		return TPromise.as(null);
+	}
+}
+
 export class ToggleReplAction extends AbstractDebugAction {
 	static ID = 'workbench.debug.action.toggleRepl';
 	static LABEL = nls.localize('toggleRepl', "Debug Console");