[sync] Prevent sessions flare on startup

chrome/browser/sync/sessions/sync_sessions_web_contents_router_unittest.cc

+// Copyright 2017 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 "chrome/browser/sync/sessions/sync_sessions_web_contents_router.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/sync/sessions/sync_sessions_web_contents_router_factory.h"
+#include "chrome/browser/ui/sync/tab_contents_synced_tab_delegate.h"
+#include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "content/public/test/web_contents_tester.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sync_sessions {
+
+class StartSyncFlareMock {
+ public:
+  StartSyncFlareMock() {}
+  ~StartSyncFlareMock() {}
+
+  void StartSyncFlare(syncer::ModelType type) { was_run_ = true; }
+
+  bool was_run() { return was_run_; }
+
+ private:
+  bool was_run_ = false;
+};
+
+class SyncSessionsWebContentsRouterTest : public testing::Test {
+ protected:
+  ~SyncSessionsWebContentsRouterTest() override {}
+
+  void SetUp() override {
+    router_ =
+        SyncSessionsWebContentsRouterFactory::GetInstance()->GetForProfile(
+            &profile_);
+    test_contents_.reset(
+        content::WebContentsTester::CreateTestWebContents(&profile_, nullptr));
+  }
+
+  SyncSessionsWebContentsRouter* router() { return router_; }
+  content::WebContents* test_contents() { return test_contents_.get(); }
+
+ private:
+  content::TestBrowserThreadBundle thread_bundle_;
+  TestingProfile profile_;
+  SyncSessionsWebContentsRouter* router_;
+  std::unique_ptr<content::WebContents> test_contents_;
+};
+
+TEST_F(SyncSessionsWebContentsRouterTest, FlareNotRun) {
+  StartSyncFlareMock mock;
+  router()->InjectStartSyncFlare(
+      base::Bind(&StartSyncFlareMock::StartSyncFlare, base::Unretained(&mock)));
+
+  // There's no delegate for the tab, so the flare shouldn't run.
+  router()->NotifyTabModified(test_contents(), false);
+  EXPECT_FALSE(mock.was_run());
+
+  TabContentsSyncedTabDelegate::CreateForWebContents(test_contents());
+
+  // There's a delegate for the tab, but it's not a load completed event, so the
+  // flare still shouldn't run.
+  router()->NotifyTabModified(test_contents(), false);
+  EXPECT_FALSE(mock.was_run());
+}
+
+TEST_F(SyncSessionsWebContentsRouterTest, FlareRunsForLoadCompleted) {
+  TabContentsSyncedTabDelegate::CreateForWebContents(test_contents());
+
+  StartSyncFlareMock mock;
+  router()->InjectStartSyncFlare(

[skym, 2017/04/18 22:39:52]

What about not having a flare and making sure we don't crash? Branch coverage!

[Patrick Noland, 2017/04/18 22:53:19]

Done.

+      base::Bind(&StartSyncFlareMock::StartSyncFlare, base::Unretained(&mock)));
+
+  // There's a delegate for the tab, and it's a load completed event, so the
+  // flare should run.
+  router()->NotifyTabModified(test_contents(), true);
+  EXPECT_TRUE(mock.was_run());
+}
+
+}  // namespace sync_sessions