predictors: Add prefetching hit/miss histograms.

chrome/browser/predictors/resource_prefetcher_unittest.cc

 // Copyright 2014 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/resource_prefetcher.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
@@ skipping 43 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(TestResourcePrefetcher);
 };
 
 
 // Delegate for ResourcePrefetcher.
 class TestResourcePrefetcherDelegate : public ResourcePrefetcher::Delegate {
  public:
   explicit TestResourcePrefetcherDelegate(base::MessageLoop* loop)
       : request_context_getter_(
             new net::TestURLRequestContextGetter(loop->task_runner())) {}
-  ~TestResourcePrefetcherDelegate() { }
+  ~TestResourcePrefetcherDelegate() override {}
 
   net::URLRequestContext* GetURLRequestContext() override {
     return request_context_getter_->GetURLRequestContext();
   }
 
-  MOCK_METHOD1(ResourcePrefetcherFinished,
-               void(ResourcePrefetcher* prefetcher));
+  void ResourcePrefetcherFinished(
+      ResourcePrefetcher* prefetcher,
+      std::unique_ptr<ResourcePrefetcher::PrefetcherStats> stats) override {
+    prefetcher_ = prefetcher;
+  }
+
+  bool ResourcePrefetcherFinishedCalled(ResourcePrefetcher* for_prefetcher) {
+    ResourcePrefetcher* prefetcher = prefetcher_;
+    prefetcher_ = nullptr;
+    return prefetcher == for_prefetcher;
+  }
 
  private:
   scoped_refptr<net::TestURLRequestContextGetter> request_context_getter_;
+  ResourcePrefetcher* prefetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(TestResourcePrefetcherDelegate);
 };
 
 
 // The following unittest tests most of the ResourcePrefetcher except for:
 // 1. Call to ReadFullResponse. There does not seem to be a good way to test the
 //    function in a unittest, and probably requires a browser_test.
 // 2. Setting of the Prefetch status for cache vs non cache.
 class ResourcePrefetcherTest : public testing::Test {
@@ skipping 129 matching lines @@
   OnResponse("http://yahoo.com/resource5.png");
   CheckPrefetcherState(3, 0, 2);
 
   OnCertificateRequested("http://m.google.com/resource4.png");
   CheckPrefetcherState(2, 0, 2);
 
   OnAuthRequired("http://m.google.com/resource3.css");
   CheckPrefetcherState(1, 0, 1);
 
   // Expect the final call.
-  EXPECT_CALL(prefetcher_delegate_,
-              ResourcePrefetcherFinished(Eq(prefetcher_.get())));
+  EXPECT_TRUE(

[alexilin, 2017/02/13 17:07:05]

This test fails.

EXPECT_CALL introduces assert that will be checked after test execution, but
your assert must be true at the call time.

You could move assert after the last OnResponse() that actually calls Delegate
or you could check assertion in a destructor of TestResourcePrefetcherDelegate.

[Benoit L, 2017/02/13 17:32:51]

Done.

+      prefetcher_delegate_.ResourcePrefetcherFinishedCalled(prefetcher_.get()));
 
   OnResponse("http://yahoo.com/resource3.png");
   CheckPrefetcherState(0, 0, 0);
 }
 
 TEST_F(ResourcePrefetcherTest, TestPrefetcherStopped) {
   GURL main_frame_url("http://www.google.com");
   std::vector<GURL> urls = {GURL("http://www.google.com/resource1.html"),
                             GURL("http://www.google.com/resource2.png"),
                             GURL("http://yahoo.com/resource1.png"),
@@ skipping 22 matching lines @@
   OnResponse("http://www.google.com/resource2.png");
   CheckPrefetcherState(3, 1, 2);
 
   OnResponse("http://yahoo.com/resource1.png");
   CheckPrefetcherState(2, 1, 2);
 
   OnResponse("http://yahoo.com/resource2.png");
   CheckPrefetcherState(1, 1, 1);
 
   // Expect the final call.
-  EXPECT_CALL(prefetcher_delegate_,
-              ResourcePrefetcherFinished(Eq(prefetcher_.get())));
+  EXPECT_TRUE(
+      prefetcher_delegate_.ResourcePrefetcherFinishedCalled(prefetcher_.get()));
 
   OnResponse("http://m.google.com/resource1.jpg");
   CheckPrefetcherState(0, 1, 0);
 }
 
 TEST_F(ResourcePrefetcherTest, TestHistogramsCollected) {
   base::HistogramTester histogram_tester;
   GURL main_frame_url("http://www.google.com");
   std::vector<GURL> urls = {GURL("http://www.google.com/resource1.png"),
                             GURL("http://www.google.com/resource2.png"),
@@ skipping 24 matching lines @@
   AddStartUrlRequestExpectation("http://www.google.com/resource6.png");
   OnAuthRequired("http://www.google.com/resource3.png");
 
   OnCertificateRequested("http://www.google.com/resource4.png");
 
   OnSSLCertificateError("http://www.google.com/resource5.png");
   histogram_tester.ExpectTotalCount(
       internal::kResourcePrefetchPredictorCachePatternHistogram, 1);
 
   // Expect the final call.
-  EXPECT_CALL(prefetcher_delegate_,
-              ResourcePrefetcherFinished(Eq(prefetcher_.get())));
+  EXPECT_TRUE(
+      prefetcher_delegate_.ResourcePrefetcherFinishedCalled(prefetcher_.get()));
 
   OnResponse("http://www.google.com/resource6.png");
   histogram_tester.ExpectTotalCount(
       internal::kResourcePrefetchPredictorCachePatternHistogram, 2);
   histogram_tester.ExpectBucketCount(
       internal::kResourcePrefetchPredictorPrefetchedCountHistogram, 2, 1);
   histogram_tester.ExpectTotalCount(
       internal::kResourcePrefetchPredictorPrefetchedSizeHistogram, 1);
 }
 
 }  // namespace predictors