fix(extensions): enable WebSQL in background pages (#24798)

* fix(extensions): enable WebSQL in background pages

* fix: apply suggestions

* fix: remove duplicate include

* fix: remove trailing spaces

shell/browser/electron_browser_client.cc

@@ -772,6 +772,16 @@ void ElectronBrowserClient::AppendExtraCommandLineSwitches(
       command_line->AppendSwitch("profile-electron-init");
     }
 
+    // Extension background pages don't have WebContentsPreferences, but they
+    // support WebSQL by default.
+#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
+    content::RenderProcessHost* process =
+        content::RenderProcessHost::FromID(process_id);
+    if (extensions::ProcessMap::Get(process->GetBrowserContext())
+            ->Contains(process_id))
+      command_line->AppendSwitch(switches::kEnableWebSQL);
+#endif
+
     content::WebContents* web_contents =
         GetWebContentsFromProcessID(process_id);
     if (web_contents) {

spec-main/extensions-spec.ts

@@ -37,6 +37,18 @@ describe('chrome extensions', () => {
     });
   });
 
+  it('can open WebSQLDatabase in a background page', async () => {
+    const customSession = session.fromPartition(`persist:${require('uuid').v4()}`);
+    const w = new BrowserWindow({ show: false, webPreferences: { session: customSession, sandbox: true } });
+    w.loadURL('about:blank');
+
+    await emittedOnce(w.webContents, 'dom-ready');
+    await customSession.loadExtension(path.join(fixtures, 'extensions', 'persistent-background-page'));
+    const args: any = await emittedOnce(app, 'web-contents-created');
+    const wc: Electron.WebContents = args[1];
+    await expect(wc.executeJavaScript('(()=>{try{openDatabase("t", "1.0", "test", 2e5);return true;}catch(e){throw e}})()')).to.not.be.rejected();
+  });
+
   function fetch (contents: WebContents, url: string) {
     return contents.executeJavaScript(`fetch(${JSON.stringify(url)})`);
   }