[SEC] Preserve Play API search engine from being replaced by prepopulated data

When search engine has valid prepopulate_id, DefaultSearchManager will
replace it with the entry from prepopulated list. This is not desired
behavior for Play API search engines as it will reset
created_from_play_api flag and search engine name and URLs.

This CL prevents DefaultSearchManager from modifying Play API search
engine.

BUG=1048713
R=pkasting@chromium.org,krb@chromium.org

Change-Id: I5e9a5e523f419b8a28953ce8f26003c1d207a451
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2037830Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Pavel Yatsuk <pavely@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739180}

components/search_engines/default_search_manager.cc

@@ -204,6 +204,14 @@ void DefaultSearchManager::MergePrefsDataWithPrepopulated() {
   if (!prefs_default_search_ || !prefs_default_search_->prepopulate_id)
     return;
 
+  // TODO(crbug.com/1049784): Parameters for search engine created from play api
+  // should be preserved even if corresponding prepopulated search engine
+  // exists. This logic will be revisited as part of implementation of
+  // crbug.com/1049784, which will enable updating play api search engine
+  // parameters with prepopulated data.
+  if (prefs_default_search_->created_from_play_api)
+    return;
+
   std::vector<std::unique_ptr<TemplateURLData>> prepopulated_urls =
       TemplateURLPrepopulateData::GetPrepopulatedEngines(pref_service_,
                                                          nullptr);

components/search_engines/default_search_manager_unittest.cc

@@ -266,3 +266,32 @@ TEST_F(DefaultSearchManagerTest, DefaultSearchSetByExtension) {
   ExpectSimilar(data.get(), manager.GetDefaultSearchEngine(&source));
   EXPECT_EQ(DefaultSearchManager::FROM_USER, source);
 }
+
+// Verify that DefaultSearchManager preserves search engine parameters for
+// search engine created from Play API data.
+TEST_F(DefaultSearchManagerTest, DefaultSearchSetByPlayAPI) {
+  DefaultSearchManager manager(pref_service(),
+                               DefaultSearchManager::ObserverCallback());
+  const TemplateURLData* prepopulated_data =
+      manager.GetDefaultSearchEngine(nullptr);
+
+  // The test tries to set DSE to the one with prepopulate_id, matching existing
+  // prepopulated search engine.
+  std::unique_ptr<TemplateURLData> data = GenerateDummyTemplateURLData(
+      base::UTF16ToUTF8(prepopulated_data->keyword()));
+  data->prepopulate_id = prepopulated_data->prepopulate_id;
+  data->favicon_url = prepopulated_data->favicon_url;
+
+  // If the new search engine was not created form Play API data its parameters
+  // should be overwritten with prepopulated data.
+  manager.SetUserSelectedDefaultSearchEngine(*data);
+  const TemplateURLData* read_data = manager.GetDefaultSearchEngine(nullptr);
+  ExpectSimilar(prepopulated_data, read_data);
+
+  // If the new search engine was created form Play API data its parameters
+  // should be preserved.
+  data->created_from_play_api = true;
+  manager.SetUserSelectedDefaultSearchEngine(*data);
+  read_data = manager.GetDefaultSearchEngine(nullptr);
+  ExpectSimilar(data.get(), read_data);
+}