[Language] Default Translate Ranker Model

1/ Add new Ranker config to field trial testing
2/ Set the default model to be consistent with the 99% Finch group

Bug: 852921
Change-Id: I04497f6a80d810a506e40b7ff9e4d1500ffc191c
Reviewed-on: https://chromium-review.googlesource.com/1179814Reviewed-by: Robert Kaplow (slow) <rkaplow@chromium.org>
Reviewed-by: Michael Martis <martis@chromium.org>
Commit-Queue: anthonyvd <anthonyvd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584791}

components/translate/core/browser/translate_ranker_impl.cc

@@ -82,7 +82,7 @@ const char kDefaultTranslateRankerModelURL[] =
 #elif defined(USE_AURA)
 const char kDefaultTranslateRankerModelURL[] =
     "https://www.gstatic.com/chrome/intelligence/assist/ranker/models/"
-    "translate/translate_ranker_20180123.model";
+    "translate/2017/03/translate_ranker_model_20170329.pb.bin";
 #else
 const char kDefaultTranslateRankerModelURL[] =
     "https://www.gstatic.com/chrome/intelligence/assist/ranker/models/"

testing/variations/fieldtrial_testing_config.json

@@ -4273,11 +4273,28 @@
         {
             "platforms": [
                 "chromeos",
-                "ios",
                 "linux",
-                "mac",
                 "windows"
             ],
+            "experiments": [
+                {
+                    "name": "launch_20180628_model_20170329_with_blacklist_override_default",
+                    "params": {
+                        "translate-ranker-model-url": "https://www.gstatic.com/chrome/intelligence/assist/ranker/models/translate/2017/03/translate_ranker_model_20170329.pb.bin"
+                    },
+                    "enable_features": [
+                        "TranslateRankerAutoBlacklistOverride",
+                        "TranslateRankerEnforcement",
+                        "TranslateRankerQuery"
+                    ]
+                }
+            ]
+        },
+        {
+            "platforms": [
+                "ios",
+                "mac"
+            ],
             "experiments": [
                 {
                     "name": "20180123_launch",