ntp_snippets: default to staging API on dev/canary

components/ntp_snippets/remote/remote_suggestions_fetcher_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/ntp_snippets/remote/remote_suggestions_fetcher.h"
 
 #include <deque>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 284 matching lines @@
     scoped_refptr<net::TestURLRequestContextGetter> request_context_getter =
         new net::TestURLRequestContextGetter(mock_task_runner_.get());
 
     fake_token_service_ = base::MakeUnique<FakeProfileOAuth2TokenService>(
         base::MakeUnique<FakeOAuth2TokenServiceDelegate>(
             request_context_getter.get()));
 
     fetcher_ = base::MakeUnique<RemoteSuggestionsFetcher>(
         utils_.fake_signin_manager(), fake_token_service_.get(),
         std::move(request_context_getter), utils_.pref_service(), nullptr,
-        base::Bind(&ParseJsonDelayed), kAPIKey, user_classifier_.get());
+        base::Bind(&ParseJsonDelayed),
+        GetFetchEndpoint(/*is_stable_or_beta_channel=*/true), kAPIKey,
+        user_classifier_.get());
 
     fetcher_->SetClockForTesting(mock_task_runner_->GetMockClock());
   }
 
   void SignIn() { utils_.fake_signin_manager()->SignIn(kTestEmail); }
 
   void IssueRefreshToken() {
     fake_token_service_->GetDelegate()->UpdateCredentials(kTestEmail, "token");
   }
 
@@ skipping 700 matching lines @@
         fetched_categories) {
   if (fetched_categories) {
     // Matchers above aren't any more precise than this, so this is sufficient
     // for test-failure diagnostics.
     return os << "list with " << fetched_categories->size() << " elements";
   }
   return os << "null";
 }
 
 }  // namespace ntp_snippets