Create LoadingDataCollector class and have observers rely on it instead of ResourcePrefetchPredictor

chrome/browser/predictors/loading_predictor_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/predictors/loading_predictor.h"
 
 #include <memory>
 #include <set>
 #include <string>
 
 #include "base/run_loop.h"
 #include "base/test/histogram_tester.h"
-#include "chrome/browser/predictors/resource_prefetch_predictor_test_util.h"
+#include "chrome/browser/predictors/loading_test_util.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace predictors {
 
 namespace {
 // First two are prefetchable, last one is not (see SetUp()).
 const char kUrl[] = "http://www.google.com/cats";
@@ skipping 186 matching lines @@
   EXPECT_EQ(start_time, it->second);
 }
 
 TEST_F(LoadingPredictorTest, TestDontTrackNonPrefetchableUrls) {
   const GURL url3 = GURL(kUrl3);
   predictor_->PrepareForPageLoad(url3, HintOrigin::EXTERNAL);
   EXPECT_TRUE(predictor_->active_hints_.empty());
 }
 
 }  // namespace predictors