base: Remove the string logging from CHECK().

headless/public/util/generic_url_request_job_test.cc

Index: headless/public/util/generic_url_request_job_test.cc
diff --git a/headless/public/util/generic_url_request_job_test.cc b/headless/public/util/generic_url_request_job_test.cc
index e1942f86e8be5b3fa255e0d72b1b4bc0bf8921d0..3adbf54cfbf5b49a09dd5f4da2aab72a3da698e2 100644
--- a/headless/public/util/generic_url_request_job_test.cc
+++ b/headless/public/util/generic_url_request_job_test.cc
@@ -47,7 +47,8 @@ class MockFetcher : public URLFetcher {
               const std::string& json_reply)
       : fetch_reply_(base::JSONReader::Read(json_reply, base::JSON_PARSE_RFC)),
         fetch_request_(fetch_request) {
-    CHECK(fetch_reply_) << "Invalid json: " << json_reply;
+    // Invalid json.
+    CHECK(fetch_reply_);
   }
 
   ~MockFetcher() override {}