[Offline Pages] Add UMA to record final offline request status and loading failed error code.

chrome/browser/android/offline_pages/background_loader_offliner.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 "chrome/browser/android/offline_pages/background_loader_offliner.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/sys_info.h"
 #include "chrome/browser/android/offline_pages/offline_page_mhtml_archiver.h"
 #include "chrome/browser/android/offline_pages/offliner_helper.h"
@@ skipping 26 matching lines @@
   BackgroundLoaderOffliner* offliner() { return offliner_; }
 
  private:
   // The offliner that the WebContents is attached to. The offliner owns the
   // Delegate which owns the WebContents that this data is attached to.
   // Therefore, its lifetime should exceed that of the WebContents, so this
   // should always be non-null.
   BackgroundLoaderOffliner* offliner_;
 };
 
+std::string AddHistogramSuffix(const ClientId& client_id,
+                               const char* histogram_name) {
+  if (client_id.name_space.empty()) {
+    NOTREACHED();
+    return histogram_name;
+  }
+  std::string adjusted_histogram_name(histogram_name);
+  adjusted_histogram_name += "." + client_id.name_space;
+  return adjusted_histogram_name;
+}
+
+void RecordErrorCauseUMA(const ClientId& client_id, net::Error error_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      AddHistogramSuffix(client_id,
+                         "OfflinePages.Background.BackgroundLoadingFailedCode"),
+      std::abs(error_code));
+}
 }  // namespace
 
 BackgroundLoaderOffliner::BackgroundLoaderOffliner(
     content::BrowserContext* browser_context,
     const OfflinerPolicy* policy,
     OfflinePageModel* offline_page_model)
     : browser_context_(browser_context),
       offline_page_model_(offline_page_model),
       is_low_end_device_(base::SysInfo::IsLowEndDevice()),
       save_state_(NONE),
@@ skipping 167 matching lines @@
     completion_callback_.Run(request, Offliner::RequestStatus::LOADING_FAILED);
     ResetState();
   }
 }
 
 void BackgroundLoaderOffliner::DidFinishNavigation(
     content::NavigationHandle* navigation_handle) {
   // If there was an error of any kind (certificate, client, DNS, etc),
   // Mark as error page. Resetting here causes RecordNavigationMetrics to crash.
   if (navigation_handle->IsErrorPage()) {
-    // TODO(chili): we need to UMA this.
+    RecordErrorCauseUMA(pending_request_->client_id(),
+                        navigation_handle->GetNetErrorCode());
     switch (navigation_handle->GetNetErrorCode()) {
       case net::ERR_ACCESS_DENIED:
       case net::ERR_ADDRESS_INVALID:
       case net::ERR_ADDRESS_UNREACHABLE:
       case net::ERR_CERT_COMMON_NAME_INVALID:
       case net::ERR_CERT_AUTHORITY_INVALID:
       case net::ERR_CERT_CONTAINS_ERRORS:
       case net::ERR_CERT_INVALID:
       case net::ERR_CONNECTION_FAILED:
       case net::ERR_DISALLOWED_URL_SCHEME:
@@ skipping 163 matching lines @@
     int64_t offline_id) {
   // If for some reason the request was reset during while waiting for callback
   // ignore the completion callback.
   if (pending_request_ && pending_request_->request_id() != offline_id)
     return;
   completion_callback_.Run(request, RequestStatus::FOREGROUND_CANCELED);
 }
 }  // namespace offline_pages
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(offline_pages::OfflinerData);