predictors: Add browsertest that tests prefetching.

chrome/browser/predictors/resource_prefetch_predictor_browsertest.cc

 // Copyright 2016 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 "base/command_line.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_factory.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_test_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "net/test/embedded_test_server/http_request.h"
 #include "net/test/embedded_test_server/http_response.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 84 matching lines @@
                   }),
       subresources.end());
   return subresources;
 }
 
 }  // namespace
 
 // Helper class to track and allow waiting for ResourcePrefetchPredictor events.
 // These events are also used to verify that ResourcePrefetchPredictor works as
 // expected.
-class ResourcePrefetchPredictorTestObserver : public TestObserver {
+class LearningObserver : public TestObserver {
  public:
   using PageRequestSummary = ResourcePrefetchPredictor::PageRequestSummary;
 
-  explicit ResourcePrefetchPredictorTestObserver(
-      ResourcePrefetchPredictor* predictor,
-      const size_t expected_url_visit_count,
-      const PageRequestSummary& expected_summary)
+  explicit LearningObserver(ResourcePrefetchPredictor* predictor,
+                            const size_t expected_url_visit_count,
+                            const PageRequestSummary& expected_summary)
       : TestObserver(predictor),
         url_visit_count_(expected_url_visit_count),
         summary_(expected_summary) {}
 
   // TestObserver:
   void OnNavigationLearned(size_t url_visit_count,
                            const PageRequestSummary& summary) override {
     EXPECT_EQ(url_visit_count, url_visit_count_);
     EXPECT_EQ(summary.main_frame_url, summary_.main_frame_url);
     EXPECT_EQ(summary.initial_url, summary_.initial_url);
     // Duplicate resources can be observed in a single navigation but
     // ResourcePrefetchPredictor only cares about the first occurrence of each.
     std::vector<ResourcePrefetchPredictor::URLRequestSummary> subresources =
         GetUniqueSubresources(summary);
     EXPECT_THAT(subresources, testing::UnorderedElementsAreArray(
                                   summary_.subresource_requests));
     run_loop_.Quit();
   }
 
   void Wait() { run_loop_.Run(); }
 
  private:
   base::RunLoop run_loop_;
   size_t url_visit_count_;
   PageRequestSummary summary_;
 
-  DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictorTestObserver);
+  DISALLOW_COPY_AND_ASSIGN(LearningObserver);
+};
+
+class PrefetchingObserver : public TestObserver {
+ public:
+  explicit PrefetchingObserver(ResourcePrefetchPredictor* predictor,
+                               const GURL& expected_main_frame_url)
+      : TestObserver(predictor), main_frame_url_(expected_main_frame_url) {}
+
+  // TestObserver:
+  void OnNavigationLearned(size_t url_visit_count,
+                           const PageRequestSummary& summary) override {
+    ADD_FAILURE() << "Prefetching shouldn't activate learning";
+  }
+
+  void OnPrefetchingFinished(const GURL& main_frame_url) override {
+    EXPECT_EQ(main_frame_url_, main_frame_url);
+    run_loop_.Quit();
+  }
+
+  void Wait() { run_loop_.Run(); }
+
+ private:
+  base::RunLoop run_loop_;
+  GURL main_frame_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefetchingObserver);
 };
 
 class ResourcePrefetchPredictorBrowserTest : public InProcessBrowserTest {
  protected:
   using URLRequestSummary = ResourcePrefetchPredictor::URLRequestSummary;
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitchASCII(
         switches::kSpeculativeResourcePrefetching,
         switches::kSpeculativeResourcePrefetchingEnabled);
@@ skipping 15 matching lines @@
 
   void NavigateToURLAndCheckSubresources(const GURL& main_frame_url) {
     GURL endpoint_url = GetRedirectEndpoint(main_frame_url);
     std::vector<URLRequestSummary> url_request_summaries;
     for (const auto& kv : resources_) {
       if (kv.second.is_no_store || !kv.second.should_be_recorded)
         continue;
       url_request_summaries.push_back(
           GetURLRequestSummaryForResource(endpoint_url, kv.second));
     }
-    ResourcePrefetchPredictorTestObserver observer(
+    LearningObserver observer(
         predictor_, UpdateAndGetVisitCount(main_frame_url),
         CreatePageRequestSummary(endpoint_url.spec(), main_frame_url.spec(),
                                  url_request_summaries));
     ui_test_utils::NavigateToURL(browser(), main_frame_url);
     observer.Wait();
+    for (auto& kv : resources_) {
+      if (!kv.second.is_no_store && kv.second.should_be_recorded)
+        kv.second.request.was_cached = true;
+    }
+  }
+
+  void PrefetchURL(const GURL& main_frame_url) {
+    PrefetchingObserver observer(predictor_, main_frame_url);
+    predictor_->StartPrefetching(main_frame_url, PrefetchOrigin::NAVIGATION);
+    observer.Wait();
+    for (auto& kv : resources_) {
+      if (!kv.second.is_no_store && kv.second.should_be_recorded)
+        kv.second.request.was_cached = true;
+    }
   }
 
   ResourceSummary* AddResource(const GURL& resource_url,
                                content::ResourceType resource_type,
                                net::RequestPriority priority) {
     auto pair_and_whether_inserted =
         resources_.insert(std::make_pair(resource_url, ResourceSummary()));
     EXPECT_TRUE(pair_and_whether_inserted.second) << resource_url
                                                   << " was inserted twice";
     ResourceSummary* resource = &pair_and_whether_inserted.first->second;
@@ skipping 25 matching lines @@
                         const std::vector<RedirectEdge>& redirect_chain) {
     ASSERT_FALSE(redirect_chain.empty());
     GURL current = initial_url;
     for (const auto& edge : redirect_chain) {
       auto result = redirects_.insert(std::make_pair(current, edge));
       EXPECT_TRUE(result.second) << current << " already has a redirect.";
       current = edge.url;
     }
   }
 
+  void ClearCache() {
+    chrome::ClearCache(browser());
+    for (auto& kv : resources_)
+      kv.second.request.was_cached = false;
+  }
+
   // Shortcut for convenience.
   GURL GetURL(const std::string& path) const {
     return embedded_test_server()->GetURL(path);
   }
 
   void EnableHttpsServer() {
     ASSERT_FALSE(https_server_);
     https_server_ = base::MakeUnique<net::EmbeddedTestServer>(
         net::EmbeddedTestServer::TYPE_HTTPS);
     https_server()->AddDefaultHandlers(
@@ skipping 236 matching lines @@
   AddResource(GetURL(kImagePath2), content::RESOURCE_TYPE_IMAGE, net::LOWEST);
   AddResource(GetURL(kStylePath2), content::RESOURCE_TYPE_STYLESHEET,
               net::HIGHEST);
   AddResource(GetURL(kScriptPath2), content::RESOURCE_TYPE_SCRIPT, net::MEDIUM);
   // Included from <iframe src="html_subresources.html"> and not recored.
   AddUnrecordedResources({GetURL(kImagePath), GetURL(kStylePath),
                           GetURL(kScriptPath), GetURL(kFontPath)});
   NavigateToURLAndCheckSubresources(GetURL(kHtmlIframePath));
 }
 
+IN_PROC_BROWSER_TEST_F(ResourcePrefetchPredictorBrowserTest,
+                       PrefetchingSimple) {
+  AddResource(GetURL(kImagePath), content::RESOURCE_TYPE_IMAGE, net::LOWEST);
+  AddResource(GetURL(kStylePath), content::RESOURCE_TYPE_STYLESHEET,
+              net::HIGHEST);
+  AddResource(GetURL(kScriptPath), content::RESOURCE_TYPE_SCRIPT, net::MEDIUM);
+  AddResource(GetURL(kFontPath), content::RESOURCE_TYPE_FONT_RESOURCE,
+              net::HIGHEST);
+  // We need to have at least two resource hits to trigger prefetch.
+  NavigateToURLAndCheckSubresources(GetURL(kHtmlSubresourcesPath));
+  ClearCache();
+  NavigateToURLAndCheckSubresources(GetURL(kHtmlSubresourcesPath));
+  ClearCache();
+  PrefetchURL(GetURL(kHtmlSubresourcesPath));
+  NavigateToURLAndCheckSubresources(GetURL(kHtmlSubresourcesPath));

[alexilin, 2016/12/06 12:44:17]

Here we reuse interceptors of URLRequests that ResourcePrefetchPredictor has and
check that all resources has actually been served from cache.

+}
+
 }  // namespace predictors