[translate] Add translate ranker model loader.

components/translate/core/browser/mock_translate_ranker.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/translate/core/browser/mock_translate_ranker.h"
+
+#include "components/metrics/proto/translate_event.pb.h"
+
+namespace translate {
+namespace testing {
+
+MockTranslateRanker::MockTranslateRanker() {}
+
+MockTranslateRanker::~MockTranslateRanker() {}
+
+bool MockTranslateRanker::IsLoggingEnabled() {
+  return is_logging_enabled_;
+}
+
+bool MockTranslateRanker::IsQueryEnabled() {
+  return is_query_enabled_ || is_logging_enabled_ || is_enforcement_enabled_;

[groby-ooo-7-16, 2017/02/14 20:56:47]

I'm not sure we should encode this behavior in the mock. I'd rather have
  CHECK(!is_logging_enabled || is_query_enabled);
  CHECK(!is_enforcement_enabled || is_query_enabled)

to force tests to fail with a badly initialized object. (It's still vulnerable
to behavior changes in the original object, but presumably new tests would flush
that out when new behavior is added - IsQueryEnabled as is would just silently
have the old behavior) 

[Roger McFarlane (Chromium), 2017/02/21 22:16:48]

Simplified this to do no implicit enabling.

+}
+
+bool MockTranslateRanker::IsEnforcementEnabled() {
+  return is_enforcement_enabled_;
+}
+
+int MockTranslateRanker::GetModelVersion() const {
+  return model_version_;
+}
+
+bool MockTranslateRanker::ShouldOfferTranslation(
+    const TranslatePrefs& /* translate_prefs */,
+    const std::string& /* src_lang */,
+    const std::string& /* dst_lang */) {
+  return should_offer_translation_;
+}
+
+void MockTranslateRanker::AddTranslateEvent(
+    const metrics::TranslateEventProto& translate_event) {
+  event_cache_.push_back(translate_event);
+}
+
+void MockTranslateRanker::FlushTranslateEvents(
+    std::vector<metrics::TranslateEventProto>* events) {
+  events->swap(event_cache_);
+  event_cache_.clear();
+}
+
+}  // namespace testing
+}  // namespace translate