Add search_terms_replacement_key field to TemplateURL.

chrome/browser/search_engines/prepopulated_engines_schema.json

Index: chrome/browser/search_engines/prepopulated_engines_schema.json
diff --git a/chrome/browser/search_engines/prepopulated_engines_schema.json b/chrome/browser/search_engines/prepopulated_engines_schema.json
index 0838e224f5100ccc3d5a0744e4ac894cabaa5e1e..ae0f1adf006263635935b42662f98402d5b6e8c2 100644
--- a/chrome/browser/search_engines/prepopulated_engines_schema.json
+++ b/chrome/browser/search_engines/prepopulated_engines_schema.json
@@ -23,9 +23,9 @@
       "optional": true
     },
     // If omitted, this engine does not support suggestions.
-    { "field": "suggest_url", "type": "string", "optional": true  },
+    { "field": "suggest_url", "type": "string", "optional": true },
     // If omitted, this engine does not support instant.
-    { "field": "instant_url", "type": "string", "optional": true  },
+    { "field": "instant_url", "type": "string", "optional": true },
     // A list of URL patterns that can be used, in addition to |search_url|,
     // to extract search terms from a URL.
     {
@@ -34,6 +34,14 @@
       "contents": { "type": "string" },
       "optional": true
     },
+    // A parameter that, if present in the query or ref parameters of a
+    // search_url or instant_url, causes Chrome to replace the URL with the
+    // search term.
+    {
+      "field": "search_terms_replacement_key",
+      "type": "string",
+      "optional": true
+    },
     {
       "field": "type",
       "type": "enum",