[LangID] Add chrome flag to allow easy local testing of the new model.

This adds an about flag for language detection that relies on TFLite.

Bug: 1182477
Change-Id: I5e569c2dc83141ad7366d6a712c35e8dc48c8664
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2721126
Commit-Queue: Michael Crouse <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Reviewed-by: Tarun Bansal <[email protected]>
Cr-Commit-Position: refs/heads/master@{#858295}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 686d37c6..9b41168 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2418,6 +2418,10 @@
     "Changes the Text Fragment background color"
     "away from the default yellow.";
 
+const char kTFLiteLanguageDetectionName[] = "TFLite-based Language Detection";
+const char kTFLiteLanguageDetectionDescription[] =
+    "Uses TFLite for language detection in place of CLD3";
+
 const char kTintCompositedContentName[] = "Tint composited content";
 const char kTintCompositedContentDescription[] =
     "Tint contents composited using Viz with a shade of red to help debug and "