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

chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc

Index: chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc
diff --git a/chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc b/chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc
index 03bd3d3fad24870cfad760a8bff170b62402a5b1..ca5d0df1e0fc919a1a892f10e2b32d460a926c43 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc
+++ b/chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc
@@ -13,6 +13,7 @@
 #include "base/test/histogram_tester.h"
 #include "chrome/browser/browsing_data/browsing_data_helper.h"
 
+#include "chrome/browser/predictors/loading_data_collector.h"
 #include "chrome/browser/predictors/loading_predictor.h"
 #include "chrome/browser/predictors/loading_predictor_factory.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_test_util.h"
@@ -368,13 +369,13 @@ class ResourcePrefetchPredictorBrowserTest : public InProcessBrowserTest {
     ASSERT_TRUE(predictor_);
     resource_prefetch_predictor_ = predictor_->resource_prefetch_predictor();
     // URLs from the test server contain a port number.
-    ResourcePrefetchPredictor::SetAllowPortInUrlsForTesting(true);
+    LoadingDataCollector::SetAllowPortInUrlsForTesting(true);
     EnsurePredictorInitialized();
     histogram_tester_.reset(new base::HistogramTester());
   }
 
   void TearDownOnMainThread() override {
-    ResourcePrefetchPredictor::SetAllowPortInUrlsForTesting(false);
+    LoadingDataCollector::SetAllowPortInUrlsForTesting(false);
   }
 
   void TestLearningAndPrefetching(