Wire up download attribution enable finch experiment

chrome/browser/safe_browsing/download_protection_service.cc

 // Copyright (c) 2012 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/safe_browsing/download_protection_service.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 20 matching lines @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/safe_browsing/download_feedback_service.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/browser/safe_browsing/sandboxed_zip_analyzer.h"
+#include "chrome/browser/sessions/session_tab_helper.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/safe_browsing/binary_feature_extractor.h"
 #include "chrome/common/safe_browsing/csd.pb.h"
 #include "chrome/common/safe_browsing/download_protection_util.h"
 #include "chrome/common/safe_browsing/file_type_policies.h"
 #include "chrome/common/safe_browsing/zip_analyzer_results.h"
 #include "chrome/common/url_constants.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
@@ skipping 15 matching lines @@
 #include "net/http/http_status_code.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_status.h"
 
 #if defined(OS_MACOSX)
 #include "chrome/browser/safe_browsing/sandboxed_dmg_analyzer_mac.h"
 #endif
 
 using content::BrowserThread;
+namespace safe_browsing {
 
 namespace {
 
 const int64_t kDownloadRequestTimeoutMs = 7000;
 // We sample 1% of whitelisted downloads to still send out download pings.
 const double kWhitelistDownloadSampleRate = 0.01;
 
+// The number of user gestures we trace back for download attribution.
+const int kDownloadAttributionUserGestureLimit = 2;
+
 const char kDownloadExtensionUmaName[] = "SBClientDownload.DownloadExtensions";
 const char kUnsupportedSchemeUmaPrefix[] = "SBClientDownload.UnsupportedScheme";
 
 enum WhitelistType {
   NO_WHITELIST_MATCH,
   URL_WHITELIST,
   SIGNATURE_WHITELIST,
   WHITELIST_TYPE_MAX
 };
 
 void RecordCountOfWhitelistedDownload(WhitelistType type) {
   UMA_HISTOGRAM_ENUMERATION("SBClientDownload.CheckWhitelistResult", type,
                             WHITELIST_TYPE_MAX);
 }
 
 }  // namespace
 
-namespace safe_browsing {
-
 const char DownloadProtectionService::kDownloadRequestUrl[] =
     "https://sb-ssl.google.com/safebrowsing/clientreport/download";
 
 const void* const DownloadProtectionService::kDownloadPingTokenKey
     = &kDownloadPingTokenKey;
 
 namespace {
 void RecordFileExtensionType(const std::string& metric_name,
                              const base::FilePath& file) {
   UMA_HISTOGRAM_SPARSE_SLOWLY(
@@ skipping 883 matching lines @@
     request.set_user_initiated(item_->HasUserGesture());
     if (type_ == ClientDownloadRequest::SAMPLED_UNSUPPORTED_FILE) {
       request.set_file_basename(
           base::FilePath(item_->GetTargetFilePath().Extension())
               .AsUTF8Unsafe());
     } else {
       request.set_file_basename(
         item_->GetTargetFilePath().BaseName().AsUTF8Unsafe());
     }
     request.set_download_type(type_);
+
+    service_->AddReferrerChainToClientDownloadRequest(
+      item_->GetURL(),
+      item_->GetWebContents(),
+      &request);
+
     if (archive_is_valid_ != ArchiveValid::UNSET)
       request.set_archive_valid(archive_is_valid_ == ArchiveValid::VALID);
     request.mutable_signature()->CopyFrom(signature_info_);
     if (image_headers_)
       request.set_allocated_image_headers(image_headers_.release());
     if (archived_executable_)
       request.mutable_archived_binary()->Swap(&archived_binary_);
     if (!request.SerializeToString(&client_download_request_data_)) {
       FinishRequest(UNKNOWN, REASON_INVALID_REQUEST_PROTO);
       return;
@@ skipping 327 matching lines @@
       if (alternate_extension.empty())
         continue;
       DCHECK_EQ(base::FilePath::kExtensionSeparator, alternate_extension[0]);
       *(request.add_alternate_extensions()) =
           base::FilePath(alternate_extension).AsUTF8Unsafe();
     }
     if (supported_path_ != default_file_path_) {
       *(request.add_alternate_extensions()) =
           base::FilePath(default_file_path_.FinalExtension()).AsUTF8Unsafe();
     }
+    service_->AddReferrerChainToClientDownloadRequest(
+      requestor_url_,
+      nullptr,
+      &request);
 
     if (!request.SerializeToString(&client_download_request_data_)) {
       // More of an internal error than anything else. Note that the UNKNOWN
       // verdict gets interpreted as "allowed".
       Finish(RequestOutcome::REQUEST_MALFORMED, UNKNOWN);
       return;
     }
 
     service_->ppapi_download_request_callbacks_.Notify(&request);
     DVLOG(2) << "Sending a PPAPI download request for URL: " << request.url();
@@ skipping 147 matching lines @@
       enabled_(false),
       binary_feature_extractor_(new BinaryFeatureExtractor()),
       download_request_timeout_ms_(kDownloadRequestTimeoutMs),
       feedback_service_(
           new DownloadFeedbackService(request_context_getter_.get(),
                                       BrowserThread::GetBlockingPool())),
       whitelist_sample_rate_(kWhitelistDownloadSampleRate) {
   if (sb_service) {
     ui_manager_ = sb_service->ui_manager();
     database_manager_ = sb_service->database_manager();
+    navigation_observer_manager_ = sb_service->navigation_observer_manager();
     ParseManualBlacklistFlag();
   }
 }
 
 DownloadProtectionService::~DownloadProtectionService() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   CancelPendingRequests();
 }
 
 void DownloadProtectionService::SetEnabled(bool enabled) {
@@ skipping 243 matching lines @@
 // static
 GURL DownloadProtectionService::GetDownloadRequestUrl() {
   GURL url(kDownloadRequestUrl);
   std::string api_key = google_apis::GetAPIKey();
   if (!api_key.empty())
     url = url.Resolve("?key=" + net::EscapeQueryParamValue(api_key, true));
 
   return url;
 }
 
+void DownloadProtectionService::AddReferrerChainToClientDownloadRequest(
+    const GURL& download_url,
+    content::WebContents* web_contents,
+    ClientDownloadRequest* out_request) {
+  if (!base::FeatureList::IsEnabled(
+      SafeBrowsingNavigationObserverManager::kDownloadAttribution) ||
+      !navigation_observer_manager_) {
+    return;
+  }
+
+  int download_tab_id = SessionTabHelper::IdForTab(web_contents);
+  UMA_HISTOGRAM_BOOLEAN(
+      "SafeBrowsing.ReferrerHasInvalidTabID.DownloadAttribution",
+      download_tab_id == -1);
+  std::vector<ReferrerChainEntry> attribution_chain;
+  SafeBrowsingNavigationObserverManager::AttributionResult result =
+      navigation_observer_manager_->IdentifyReferrerChain(
+          download_url,
+          download_tab_id,
+          kDownloadAttributionUserGestureLimit,
+          &attribution_chain);
+  UMA_HISTOGRAM_COUNTS_100(
+      "SafeBrowsing.ReferrerURLChainSize.DownloadAttribution",
+      attribution_chain.size());
+  UMA_HISTOGRAM_ENUMERATION(
+      "SafeBrowsing.ReferrerAttributionResult.DownloadAttribution", result,
+      SafeBrowsingNavigationObserverManager::ATTRIBUTION_FAILURE_TYPE_MAX);
+  for (auto entry : attribution_chain)
+    *out_request->add_referrer_chain() = std::move(entry);
+}
+
 }  // namespace safe_browsing