Make OnDataTimedout and OnDidPerformInstallableCheck mutually exclusive.

chrome/browser/android/webapps/add_to_homescreen_data_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 "chrome/browser/android/webapps/add_to_homescreen_data_fetcher.h"
 
 #include <memory>
 #include <string>
 
 #include "base/callback_forward.h"
@@ skipping 15 matching lines @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/manifest.h"
 #include "content/test/test_web_contents.h"
 #include "net/http/http_status_code.h"
 #include "third_party/WebKit/public/platform/WebDisplayMode.h"
 #include "ui/gfx/image/image_unittest_util.h"
 #include "url/gurl.h"
 
+// TODO(zpeng): Effectively test scenarios where both timeout callback and
+// success callback are invoked. See crbug.com/697228.
+
 namespace {
 
 const char* kDefaultManifestUrl = "https://www.example.com/manifest.json";
 const char* kDefaultManifestName = "Default Name";
 const char* kDefaultManifestShortName = "Default Short Name";
 const char* kDefaultStartUrl = "https://www.example.com/index.html";
 const blink::WebDisplayMode kDefaultManifestDisplayMode =
     blink::WebDisplayModeStandalone;
 
 // WebContents subclass which mocks out image and manifest fetching.
@@ skipping 313 matching lines @@
     }
     // This callback enables the text field in the add-to-homescreen dialog.
     EXPECT_TRUE(waiter.title_available());
 
     fetcher->set_weak_observer(nullptr);
 }
 
 INSTANTIATE_TEST_CASE_P(CheckWebApkCompatibility,
                         AddToHomescreenDataFetcherTestCommon,
                         ::testing::Values(false, true));