predictors: Refactor resource_prefetch_predictor triggering.

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 <string>
+
+#include "base/run_loop.h"
+#include "base/test/histogram_tester.h"
+#include "chrome/browser/predictors/resource_prefetch_predictor_test_util.h"
+#include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace predictors {
+
+class LoadingPredictorTest : public testing::Test {
+ public:
+  LoadingPredictorTest();
+  ~LoadingPredictorTest() override;
+  void SetUp() override;
+  void TearDown() override;
+
+ protected:
+  std::unique_ptr<LoadingPredictor> predictor_;
+  content::TestBrowserThreadBundle thread_bundle_;

[alexilin, 2017/05/30 16:19:14]

Nit: thread_bundle_ must be the first member.
https://cs.chromium.org/chromium/src/content/public/test/test_browser_thread_...

[Benoit L, 2017/05/31 14:34:42]

Thanks!
Done.

+  std::unique_ptr<TestingProfile> profile_;
+};
+
+LoadingPredictorTest::LoadingPredictorTest()
+    : profile_(base::MakeUnique<TestingProfile>()) {}
+
+LoadingPredictorTest::~LoadingPredictorTest() {
+  profile_ = nullptr;
+  base::RunLoop().RunUntilIdle();
+}
+
+void LoadingPredictorTest::SetUp() {
+  LoadingPredictorConfig config;
+  PopulateTestConfig(&config);
+  predictor_ = base::MakeUnique<LoadingPredictor>(config, profile_.get());
+  predictor_->StartInitialization();
+  base::RunLoop loop;

[alexilin, 2017/05/30 16:19:14]

tiny nit:
Why not base::RunLoop.RunUntilIdle() as above?

[Benoit L, 2017/05/31 14:34:42]

Done.

+  loop.RunUntilIdle();  // Runs the DB lookup.
+}
+
+void LoadingPredictorTest::TearDown() {
+  predictor_ = nullptr;
+  profile_->DestroyHistoryService();
+}
+
+TEST_F(LoadingPredictorTest, TestPrefetchingDurationHistogram) {
+  base::HistogramTester histogram_tester;
+
+  const GURL url = GURL("http://www.google.com/cats");
+  const GURL url2 = GURL("http://www.notgoogle.com/dogs");
+
+  predictor_->PrepareForPageLoad(url, HintOrigin::EXTERNAL);
+  predictor_->CancelPageLoadHint(url);
+  histogram_tester.ExpectTotalCount(
+      internal::kResourcePrefetchPredictorPrefetchingDurationHistogram, 1);
+
+  // Mismatched start / end.
+  predictor_->PrepareForPageLoad(url, HintOrigin::EXTERNAL);
+  predictor_->CancelPageLoadHint(url2);
+  // No increment.
+  histogram_tester.ExpectTotalCount(
+      internal::kResourcePrefetchPredictorPrefetchingDurationHistogram, 1);
+
+  // Can track a navigation (url2) while one is still in progress (url).
+  predictor_->PrepareForPageLoad(url2, HintOrigin::EXTERNAL);
+  predictor_->CancelPageLoadHint(url2);
+  histogram_tester.ExpectTotalCount(
+      internal::kResourcePrefetchPredictorPrefetchingDurationHistogram, 2);
+}
+
+TEST_F(LoadingPredictorTest, TestMainFrameResponseCancelHint) {

[alexilin, 2017/05/30 16:19:14]

nit:
s/Cancel/Cancels/

[Benoit L, 2017/05/31 14:34:42]

Done.

+  const GURL url = GURL("http://www.google.com/cats");
+
+  predictor_->PrepareForPageLoad(url, HintOrigin::EXTERNAL);
+  EXPECT_EQ(1UL, predictor_->active_hints_.size());
+
+  auto summary = CreateURLRequestSummary(12, url.spec());
+  predictor_->OnMainFrameResponse(summary);
+  EXPECT_TRUE(predictor_->active_hints_.empty());
+}
+
+TEST_F(LoadingPredictorTest, TestMainFrameRequestCancelStaleNavigations) {

[alexilin, 2017/05/30 16:19:14]

ditto

[Benoit L, 2017/05/31 14:34:42]

Done.

+  const std::string url = "http://www.google.com/cats";
+  const std::string url2 = "http://www.notgoogle.com/dogs";
+  const int tab_id = 12;
+  const auto& active_navigations = predictor_->active_navigations_;
+  const auto& active_hints = predictor_->active_hints_;
+
+  auto summary = CreateURLRequestSummary(tab_id, url);
+  auto navigation_id = CreateNavigationID(tab_id, url);
+
+  predictor_->OnMainFrameRequest(summary);
+  EXPECT_NE(active_navigations.find(navigation_id), active_navigations.end());
+  EXPECT_NE(active_hints.find(GURL(url)), active_hints.end());
+
+  summary = CreateURLRequestSummary(tab_id, url2);
+  predictor_->OnMainFrameRequest(summary);
+  EXPECT_EQ(active_navigations.find(navigation_id), active_navigations.end());
+  EXPECT_EQ(active_hints.find(GURL(url)), active_hints.end());
+
+  auto navigation_id2 = CreateNavigationID(tab_id, url2);
+  EXPECT_NE(active_navigations.find(navigation_id2), active_navigations.end());
+}
+
+TEST_F(LoadingPredictorTest, TestMainFrameResponseClearsNavigation) {
+  const std::string url = "http://www.google.com/cats";
+  const std::string redirected = "http://www.google.com/dogs";
+  const int tab_id = 12;
+  const auto& active_navigations = predictor_->active_navigations_;
+  const auto& active_hints = predictor_->active_hints_;
+
+  auto summary = CreateURLRequestSummary(tab_id, url);
+  auto navigation_id = CreateNavigationID(tab_id, url);
+
+  predictor_->OnMainFrameRequest(summary);
+  EXPECT_NE(active_navigations.find(navigation_id), active_navigations.end());
+  EXPECT_FALSE(active_hints.empty());
+
+  predictor_->OnMainFrameResponse(summary);
+  EXPECT_TRUE(active_navigations.empty());
+  EXPECT_TRUE(active_hints.empty());
+
+  // With redirects.
+  predictor_->OnMainFrameRequest(summary);
+  EXPECT_NE(active_navigations.find(navigation_id), active_navigations.end());
+  EXPECT_FALSE(active_hints.empty());
+
+  summary.redirect_url = GURL(redirected);
+  predictor_->OnMainFrameRedirect(summary);
+  EXPECT_FALSE(active_navigations.empty());
+  EXPECT_FALSE(active_hints.empty());
+
+  summary.navigation_id.main_frame_url = GURL(redirected);
+  predictor_->OnMainFrameResponse(summary);
+  EXPECT_TRUE(active_navigations.empty());
+  EXPECT_TRUE(active_hints.empty());
+}
+
+}  // namespace predictors

[alexilin, 2017/05/30 16:19:14]

Another useful usecase:
OnMainFrameRequest doesn't cancel previously received external hint for the same
url.

[Benoit L, 2017/05/31 14:34:42]

Done.