Bug 1892514 - part 5-3: Enable the assertions in `IMEContentObserver::FlatTextCache` in some automated tests r=smaug

This patch enables the assertions when running:
* The `nsITextInputProcessor` tests
* The IME composition tests under `widget/`
* Under `editor/libeditor/tests`
* Under `editor/libeditor/crashtests`
* Under testing/web-platform/tests/editing`
* Under testing/web-platform/tests/input-events`

Differential Revision: https://phabricator.services.mozilla.com/D211835

dom/base/test/chrome/test_nsITextInputProcessorCallback_at_changing_default_value_of_textarea.html

@@ -10,6 +10,10 @@
 
 SimpleTest.waitForExplicitFinish();
 SimpleTest.waitForFocus(async () => {
+  await SpecialPowers.pushPrefEnv({
+    set: [["test.ime_content_observer.assert_invalid_cache", true]],
+  });
+
   const textarea = document.createElement("textarea");
   document.body.appendChild(textarea);
   textarea.focus();

dom/base/test/chrome/window_nsITextInputProcessor.xhtml

@@ -4966,6 +4966,10 @@ async function runTextNotificationChangesDuringNoFrame() {
 
 async function runTests()
 {
+  await SpecialPowers.pushPrefEnv({
+    set: [["test.ime_content_observer.assert_invalid_cache", true]],
+  });
+
   textareaInFrame = iframe.contentDocument.getElementById("textarea");
   runBeginInputTransactionMethodTests();
   runReleaseTests();

dom/base/test/test_text_change_notifications_when_inserting_text_containing_line_breaks.html

@@ -9,6 +9,10 @@
 
 SimpleTest.waitForExplicitFinish();
 SimpleTest.waitForFocus(async () => {
+  await SpecialPowers.pushPrefEnv({
+    set: [["test.ime_content_observer.assert_invalid_cache", true]],
+  });
+
   const editingHost = document.querySelector("div[contenteditable]");
   const TIP = SpecialPowers.Cc["@mozilla.org/text-input-processor;1"].createInstance(
     SpecialPowers.Ci.nsITextInputProcessor

dom/events/test/test_text_event_in_content.html

@@ -12,7 +12,10 @@
 <div contenteditable id="editor"><p><br></p></div>
 <script>
 SimpleTest.waitForExplicitFinish();
-SimpleTest.waitForFocus(function doTests() {
+SimpleTest.waitForFocus(async function doTests() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["test.ime_content_observer.assert_invalid_cache", true]],
+  });
   for (let editorId of ["input", "textarea", "editor"]) {
     let editor = document.getElementById(editorId);
     editor.focus();

editor/libeditor/crashtests/crashtests.list

@@ -1,3 +1,5 @@
+defaults pref(test.ime_content_observer.assert_invalid_cache,true)
+
 load 336081-1.xhtml
 load 403965-1.xhtml
 load 428489-1.html

editor/libeditor/tests/browser.toml

@@ -1,4 +1,5 @@
 [DEFAULT]
+prefs = ["test.ime_content_observer.assert_invalid_cache=true"]
 skip-if = ["os == 'android'"]
 
 ["browser_bug527935.js"]

editor/libeditor/tests/chrome.toml

@@ -1,4 +1,5 @@
 [DEFAULT]
+prefs = ["test.ime_content_observer.assert_invalid_cache=true"]
 skip-if = ["os == 'android'"]
 
 ["test_bug489202.xhtml"]

editor/libeditor/tests/mochitest.toml

@@ -1,6 +1,7 @@
 [DEFAULT]
 prefs = [
   "apz.zoom-to-focused-input.enabled=false",
+  "test.ime_content_observer.assert_invalid_cache=true",
   "ui.dragThresholdX=4", # Bug 1873142
   "ui.dragThresholdY=4", # Bug 1873142
 ]

testing/web-platform/meta/editing/__dir__.ini

@@ -0,0 +1 @@
+prefs: [test.ime_content_observer.assert_invalid_cache:true]

testing/web-platform/meta/input-events/__dir__.ini

@@ -1 +1,2 @@
+prefs: [test.ime_content_observer.assert_invalid_cache:true]
 leak-threshold: [default:51200]

widget/tests/window_composition_text_querycontent.xhtml

@@ -10870,7 +10870,10 @@ async function runInputModeTest()
 async function runTest()
 {
   await SpecialPowers.pushPrefEnv({
-    set: [["dom.events.textevent.enabled", true]],
+    set: [
+      ["dom.events.textevent.enabled", true],
+      ["test.ime_content_observer.assert_invalid_cache", true],
+    ],
   });
 
   window.addEventListener("unload", window.arguments[0].SimpleTest.finish, {once: true, capture: true});