predictors: Add prefetcher histograms for speculative prefetch.

chrome/browser/predictors/resource_prefetcher_unittest.cc

Index: chrome/browser/predictors/resource_prefetcher_unittest.cc
diff --git a/chrome/browser/predictors/resource_prefetcher_unittest.cc b/chrome/browser/predictors/resource_prefetcher_unittest.cc
index 80631b977d00c9de072ed96d48bb3a5cfeb1e0f1..a412b552bcdab7ea207a15af92f6deee54fdc0f5 100644
--- a/chrome/browser/predictors/resource_prefetcher_unittest.cc
+++ b/chrome/browser/predictors/resource_prefetcher_unittest.cc
@@ -13,6 +13,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
+#include "base/test/histogram_tester.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_test_util.h"
 #include "chrome/browser/predictors/resource_prefetcher_manager.h"
 #include "chrome/test/base/testing_profile.h"
@@ -45,6 +46,7 @@ class TestResourcePrefetcher : public ResourcePrefetcher {
 
   void ReadFullResponse(net::URLRequest* request) override {
     EXPECT_TRUE(request->load_flags() & net::LOAD_PREFETCH);
+    RequestComplete(request);
     FinishRequest(request);
   }
 
@@ -165,8 +167,6 @@ TEST_F(ResourcePrefetcherTest, TestPrefetcherFinishes) {
                             GURL("http://yahoo.com/resource4.png"),
                             GURL("http://yahoo.com/resource5.png")};
 
-  NavigationID navigation_id = CreateNavigationID(1, main_frame_url.spec());
-
   prefetcher_.reset(new TestResourcePrefetcher(&prefetcher_delegate_, config_,
                                                main_frame_url, urls));
 
@@ -237,8 +237,6 @@ TEST_F(ResourcePrefetcherTest, TestPrefetcherStopped) {
                             GURL("http://yahoo.com/resource3.png"),
                             GURL("http://m.google.com/resource1.jpg")};
 
-  NavigationID navigation_id = CreateNavigationID(1, main_frame_url.spec());
-
   prefetcher_.reset(new TestResourcePrefetcher(&prefetcher_delegate_, config_,
                                                main_frame_url, urls));
 
@@ -274,4 +272,55 @@ TEST_F(ResourcePrefetcherTest, TestPrefetcherStopped) {
   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"),
+                            GURL("http://www.google.com/resource3.png"),
+                            GURL("http://www.google.com/resource4.png"),
+                            GURL("http://www.google.com/resource5.png"),
+                            GURL("http://www.google.com/resource6.png")};
+
+  prefetcher_ = base::MakeUnique<TestResourcePrefetcher>(
+      &prefetcher_delegate_, config_, main_frame_url, urls);
+
+  // Starting the prefetcher maxes out the number of possible requests.
+  AddStartUrlRequestExpectation("http://www.google.com/resource1.png");
+  AddStartUrlRequestExpectation("http://www.google.com/resource2.png");
+  AddStartUrlRequestExpectation("http://www.google.com/resource3.png");
+
+  prefetcher_->Start();
+
+  AddStartUrlRequestExpectation("http://www.google.com/resource4.png");
+  OnResponse("http://www.google.com/resource1.png");
+  histogram_tester.ExpectTotalCount(
+      internal::kResourcePrefetchPredictorCachePatternHistogram, 1);
+
+  // Failed prefetches aren't counted.
+  AddStartUrlRequestExpectation("http://www.google.com/resource5.png");
+  OnReceivedRedirect("http://www.google.com/resource2.png");
+
+  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())));
+
+  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