predictors: Refactor resource_prefetch_predictor triggering.

chrome/browser/predictors/resource_prefetch_predictor.h

Index: chrome/browser/predictors/resource_prefetch_predictor.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.h b/chrome/browser/predictors/resource_prefetch_predictor.h
index 2cd3c950895ace6aabeb4aa0cf8d2067fa9263e0..38d2d0765b7c99d4216ccb7b1597bb13c119cb3d 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor.h
@@ -23,6 +23,7 @@
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_tables.h"
 #include "chrome/browser/predictors/resource_prefetcher.h"
+#include "chrome/browser/predictors/resource_prefetcher_manager.h"
 #include "components/history/core/browser/history_db_task.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/history/core/browser/history_types.h"
@@ -244,7 +245,7 @@ class ResourcePrefetchPredictor
       std::unique_ptr<ResourcePrefetcher::PrefetcherStats> stats);
 
   // Returns true if prefetching data exists for the |main_frame_url|.
-  virtual bool IsUrlPrefetchable(const GURL& main_frame_url);
+  virtual bool IsUrlPrefetchable(const GURL& main_frame_url) const;
 
   // Returns true iff |resource| has sufficient confidence level and required
   // number of hits.
@@ -260,6 +261,10 @@ class ResourcePrefetchPredictor
   void SetObserverForTesting(TestObserver* observer);
 
  private:
+  // Return whether the predictor has data about a URL and can prefetch it
+  // for a given origin with the current configuration.
+  bool CanPrefetchUrlForOrigin(const GURL& url, HintOrigin origin) const;
+
   // Starts prefetching if it is enabled for |origin| and prefetching data
   // exists for the |main_frame_url| either at the URL or at the host level.
   void StartPrefetching(const GURL& main_frame_url, HintOrigin origin);
@@ -309,6 +314,8 @@ class ResourcePrefetchPredictor
                            TestPrefetchingDurationHistogram);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            TestRecordFirstContentfulPaint);
+  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
+                           TestCanPrefetchUrlForOrigin);
 
   enum InitializationState {
     NOT_INITIALIZED = 0,
@@ -473,6 +480,12 @@ class ResourcePrefetchPredictor
     tables_ = tables;
   }
 
+  // For testing.
+  void set_mock_resource_prefetcher_manager(
+      scoped_refptr<ResourcePrefetcherManager> prefetch_manager) {
+    prefetch_manager_ = prefetch_manager;
+  }
+
   Profile* const profile_;
   TestObserver* observer_;
   const LoadingPredictorConfig config_;