Bug 1735161 - Update MDN URL in speculation failure message. r=smaug DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D128095

dom/locales/en-US/chrome/dom/dom.properties

@@ -23,7 +23,7 @@ OnBeforeUnloadMessage2=This page is asking you to confirm that you want to leave
 OnBeforeUnloadStayButton=Stay on page
 OnBeforeUnloadLeaveButton=Leave page
 EmptyGetElementByIdParam=Empty string passed to getElementById().
-SpeculationFailed=An unbalanced tree was written using document.write() causing data from the network to be reparsed. For more information https://developer.mozilla.org/en/Optimizing_Your_Pages_for_Speculative_Parsing
+SpeculationFailed2=An unbalanced tree was written using document.write() causing data from the network to be reparsed. More information: https://developer.mozilla.org/en-US/docs/Glossary/speculative_parsing
 DocumentWriteIgnored=A call to document.write() from an asynchronously-loaded external script was ignored.
 # LOCALIZATION NOTE (EditorFileDropFailed): Do not translate contenteditable, %S is the error message explaining why the drop failed.
 EditorFileDropFailed=Dropping a file into a contenteditable element failed: %S.

parser/html/nsHtml5StreamParser.cpp

@@ -1969,7 +1969,7 @@ void nsHtml5StreamParser::ContinueAfterScripts(nsHtml5Tokenizer* aTokenizer,
       nsContentUtils::ReportToConsole(
           nsIScriptError::warningFlag, "DOM Events"_ns,
           mExecutor->GetDocument(), nsContentUtils::eDOM_PROPERTIES,
-          "SpeculationFailed", nsTArray<nsString>(), nullptr, u""_ns,
+          "SpeculationFailed2", nsTArray<nsString>(), nullptr, u""_ns,
           speculation->GetStartLineNumber());
 
       nsHtml5OwningUTF16Buffer* buffer = mFirstBuffer->next;