ErrorPage: use case-insensitive check for text

chrome/browser/net/errorpage_browsertest.cc

Index: chrome/browser/net/errorpage_browsertest.cc
diff --git a/chrome/browser/net/errorpage_browsertest.cc b/chrome/browser/net/errorpage_browsertest.cc
index dfd12f392b20b57efa41098c4cff8713d47c841c..ec0fdef5a5333b3dc856ed8f9c991a09569bad3f 100644
--- a/chrome/browser/net/errorpage_browsertest.cc
+++ b/chrome/browser/net/errorpage_browsertest.cc
@@ -95,8 +95,8 @@ namespace {
 bool WARN_UNUSED_RESULT IsDisplayingText(Browser* browser,
                                          const std::string& text) {
   std::string command = base::StringPrintf(
-      "var textContent = document.body.innerText;"
-      "var hasText = textContent.indexOf('%s') >= 0;"
+      "var textContent = document.body.innerText.toLowerCase();"
+      "var hasText = textContent.indexOf('%s'.toLowerCase()) >= 0;"
       "domAutomationController.send(hasText);",
       text.c_str());
   bool result = false;