DevTools: Ensure unhandled exception doesn't prevent clearing of indexeddb data

In the event there are multiple targets on page, clearing the storage via the applications
tab can result in:
  console.assert(this._databaseNamesBySecurityOrigin[securityOrigin]);
firing in Resources.IndexedDBModel.clearForOrigin because only the top
level security origin is passed to each target, and the security origins might
not match.

Repro steps:

1) Load http://nparashuram.com/trialtool/#example=/IndexedDB/trialtool/index.html&selected=#saveData
2) Run the following examples: "Pre Requisities", "Open Database", "Create Object Store", "Add Data"
3) Load the devtools, and clear all site data from the application tab

Change-Id: Iccad7f70c61eb6593058280f971849f139f473a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1716445
Commit-Queue: Mike Jackson <mjackson@microsoft.com>
Reviewed-by: Erik Luo <luoe@chromium.org>
Reviewed-by: Jeff Fisher <jeffish@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#690782}

third_party/blink/renderer/devtools/front_end/resources/IndexedDBModel.js

@@ -160,7 +160,7 @@ Resources.IndexedDBModel = class extends SDK.SDKModel {
    * @param {string} origin
    */
   clearForOrigin(origin) {
-    if (!this._enabled)
+    if (!this._enabled || !this._databaseNamesBySecurityOrigin[origin])
       return;
 
     this._removeOrigin(origin);

third_party/blink/web_tests/http/tests/devtools/application-panel/resources-panel-idb-clear-for-origin-expected.txt

+Validate IndexeddbModel clearForOrigin
+
+Create IndexedDB in main frame
+Database Length: 1
+Database Entries:
+  Security Origin:http://127.0.0.1:8000, Database Name:Database-main-frame
+**done**
+
+Removing bogus security origin...
+Database Length: 1
+Database Entries:
+  Security Origin:http://127.0.0.1:8000, Database Name:Database-main-frame
+**done**
+
+Removing http://127.0.0.1:8000 security origin...
+Database Length: 0
+Database Entries:
+**done**
+
+

third_party/blink/web_tests/http/tests/devtools/application-panel/resources-panel-idb-clear-for-origin.js

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(async function() {
+  TestRunner.addResult(`Validate IndexeddbModel clearForOrigin\n`);
+  await TestRunner.loadModule('application_test_runner');
+  // Note: every test that uses a storage API must manually clean-up state from previous tests.
+  await ApplicationTestRunner.resetState();
+
+  await TestRunner.loadModule('console_test_runner');
+  await TestRunner.showPanel('resources');
+
+  const model = TestRunner.mainTarget.model(Resources.IndexedDBModel);
+  const view = UI.panels.resources;
+
+  function createIndexedDBInMainFrame(callback) {
+    var mainFrameId = TestRunner.resourceTreeModel.mainFrame.id;
+    ApplicationTestRunner.createDatabase(mainFrameId, 'Database-main-frame', () => {
+      var event = model.addEventListener(Resources.IndexedDBModel.Events.DatabaseAdded, () => {
+        Common.EventTarget.removeEventListeners([event]);
+        callback();
+      });
+      model.refreshDatabaseNames();
+    });
+  }
+
+  function dumpDatabases() {
+    const databases = model.databases();
+    TestRunner.addResult('Database Length: ' + databases.length);
+    TestRunner.addResult('Database Entries:');
+    for (let j = 0; j < databases.length; ++j)
+      TestRunner.addResult(`  Security Origin:${databases[j].securityOrigin}, Database Name:${databases[j].name}`);
+    TestRunner.addResult('**done**\n');
+  }
+
+  TestRunner.addResult('Create IndexedDB in main frame');
+  await new Promise(createIndexedDBInMainFrame);
+  await TestRunner.addSnifferPromise(UI.panels.resources._sidebar.indexedDBListTreeElement, '_indexedDBLoadedForTest');
+  dumpDatabases();
+
+  TestRunner.addResult('Removing bogus security origin...');
+  model.clearForOrigin('http://bogus-security-origin.com');
+  dumpDatabases();
+
+  TestRunner.addResult('Removing http://127.0.0.1:8000 security origin...');
+  model.clearForOrigin('http://127.0.0.1:8000');
+  dumpDatabases();
+
+  TestRunner.completeTest();
+})();