predictors: Refactor resource_prefetch_predictor triggering.

chrome/browser/predictors/loading_predictor.h

Index: chrome/browser/predictors/loading_predictor.h
diff --git a/chrome/browser/predictors/loading_predictor.h b/chrome/browser/predictors/loading_predictor.h
index 9bcdd81fec861b45e1897c201c14f70d8aaced53..4588febb7875effa49ae3b11be25447fee945cb9 100644
--- a/chrome/browser/predictors/loading_predictor.h
+++ b/chrome/browser/predictors/loading_predictor.h
@@ -5,12 +5,17 @@
 #ifndef CHROME_BROWSER_PREDICTORS_LOADING_PREDICTOR_H_
 #define CHROME_BROWSER_PREDICTORS_LOADING_PREDICTOR_H_
 
+#include <map>
 #include <memory>
+#include <utility>
 
+#include "base/gtest_prod_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 #include "components/keyed_service/core/keyed_service.h"
+#include "url/gurl.h"
 
 class Profile;
 
@@ -22,6 +27,9 @@ class ResourcePrefetchPredictor;
 // From a high-level request (GURL and motivation) and a database of historical
 // data, initiates predictive actions to speed up page loads.
 //
+// Also listens to main frame requests/redirects/responses to initiate and
+// cancel page load hints.
+//
 // See ResourcePrefetchPredictor for a description of the resource prefetch
 // predictor.
 //
@@ -48,8 +56,45 @@ class LoadingPredictor : public KeyedService,
   // KeyedService:
   void Shutdown() override;
 
+  void OnMainFrameRequest(
+      const ResourcePrefetchPredictor::URLRequestSummary& summary);
+  void OnMainFrameRedirect(
+      const ResourcePrefetchPredictor::URLRequestSummary& summary);
+  void OnMainFrameResponse(
+      const ResourcePrefetchPredictor::URLRequestSummary& summary);
+
  private:
+  // Cancels an active hint, from its iterator inside |active_hints_|. If the
+  // iterator is .end(), does nothing. Returns the iterator after deletion of
+  // the entry.
+  std::map<GURL, base::TimeTicks>::iterator CancelActiveHint(
+      std::map<GURL, base::TimeTicks>::iterator hint_it);
+  void CleanupAbandonedHintsAndNavigations(const NavigationID& navigation_id);
+
+  // For testing.
+  void set_mock_resource_prefetch_predictor(
+      std::unique_ptr<ResourcePrefetchPredictor> predictor) {
+    resource_prefetch_predictor_ = std::move(predictor);
+  }
+
+  LoadingPredictorConfig config_;
+  Profile* profile_;
   std::unique_ptr<ResourcePrefetchPredictor> resource_prefetch_predictor_;
+  std::map<GURL, base::TimeTicks> active_hints_;
+  // Initial URL.
+  std::map<NavigationID, GURL> active_navigations_;
+
+  friend class LoadingPredictorTest;

[alexilin, 2017/05/31 16:02:03]

nit:
Usually we put friends declarations closer to the beginning of the private
section. It's up to you.

+  FRIEND_TEST_ALL_PREFIXES(LoadingPredictorTest,
+                           TestMainFrameResponseCancelsHint);
+  FRIEND_TEST_ALL_PREFIXES(LoadingPredictorTest,
+                           TestMainFrameRequestCancelsStaleNavigations);
+  FRIEND_TEST_ALL_PREFIXES(LoadingPredictorTest,
+                           TestMainFrameResponseClearsNavigations);
+  FRIEND_TEST_ALL_PREFIXES(LoadingPredictorTest,
+                           TestMainFrameRequestDoesntCancelExternalHint);
+  FRIEND_TEST_ALL_PREFIXES(LoadingPredictorTest,
+                           TestDontTrackNonPrefetchableUrls);
 
   DISALLOW_COPY_AND_ASSIGN(LoadingPredictor);
 };